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TP63

TP63, also known as tumor protein p63, is a gene located on the long arm of chromosome 3 at position 3q28 that encodes the p63 protein, a transcription factor belonging to the p53 family of proteins. The p63 protein regulates the expression of numerous genes involved in cell proliferation, differentiation, adhesion, and programmed cell death (apoptosis), playing a pivotal role in the development and maintenance of stratified epithelial tissues such as skin, hair, nails, and mucous membranes. Unlike its family member p53, which is primarily a tumor suppressor, p63 is essential for embryonic development, particularly in ectodermal-derived structures like limbs, craniofacial features, and the urinary tract, with knockout studies in mice revealing severe defects in skin stratification and limb morphogenesis. The TP63 gene produces multiple protein isoforms through alternative promoter usage and splicing, including transactivating (TA) isoforms that promote gene expression similar to and dominant-negative (ΔN) isoforms that inhibit it, allowing context-specific functions in tissue and stress responses. These isoforms are predominantly expressed in basal cells of epithelial tissues, where p63 maintains populations and supports regenerative processes throughout life. In , p63 coordinates epithelial-mesenchymal interactions, ensuring proper formation of appendages and barriers; for instance, it regulates genes such as DLX5 for limb and PERP for . Mutations in TP63 are associated with a spectrum of autosomal dominant ectodermal dysplasia syndromes, characterized by abnormalities in skin, hair, teeth, nails, limbs, and craniofacial structures, including ankyloblepharon-ectodermal defects-cleft lip/palate (AEC) syndrome, ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome, limb-mammary syndrome (LMS), split hand/foot malformation type 4 (SHFM4), and ADULT syndrome. These mutations often result in gain-of-function or dominant-negative effects that disrupt p63's transcriptional activity, leading to impaired ectodermal differentiation and increased apoptosis in progenitor cells. Additionally, certain TP63 variants contribute to isolated conditions like orofacial clefting and premature ovarian insufficiency. In , TP63 exhibits a depending on isoform and tumor type: ΔN isoforms are frequently overexpressed in squamous cell carcinomas (e.g., of the head, , , and ), acting as oncogenes by promoting and through enhancer reprogramming and suppression of , while TA isoforms often function as tumor suppressors by inducing and maintaining genomic stability. Overexpression of ΔNp63α correlates with poor in low-grade squamous tumors, whereas loss of TP63 expression facilitates in advanced stages, highlighting its context-dependent regulation in cancer progression.

Gene and Protein Overview

Genomic Organization and Location

The TP63 is located on the long arm of human at cytogenetic band q28, spanning genomic coordinates 189,596,746 to 189,897,276 on the forward strand in the GRCh38.p14 assembly, which corresponds to approximately 189.60–189.90 Mb. This positioning places TP63 within a region associated with various developmental and oncogenic processes, though the focus here remains on its structural features. The encompasses roughly kilobases (kb) of genomic DNA, providing ample space for regulatory elements that modulate its expression across tissues. Structurally, TP63 comprises 15 s, with alternative promoter usage and splicing events generating multiple transcript variants. The primary upstream promoter (P1) initiates transcription of full-length transactivating (TA) isoforms, while an internal promoter (P2) within intron 3 drives dominant-negative (ΔN) isoforms lacking the N-terminal . These alternative promoters, along with variable 3' splicing, yield at least six major protein-coding transcripts, enabling tissue-specific expression patterns. Upstream of the P1 promoter, regulatory elements such as enhancers and binding sites for transcription factors contribute to precise control of TP63 transcription during development and . TP63 exhibits strong evolutionary conservation across s, reflecting its fundamental role in multicellular organisms, and belongs to the family of transcription factors alongside TP53 and TP73. in the DNA-binding and oligomerization domains is particularly high (over 60% identity with TP53), suggesting a common ancestral that duplicated early in . Orthologs of TP63 are identifiable in diverse , from fish to mammals, underscoring its preservation through selective pressure for epithelial and developmental functions.

Isoforms and Structural Features

The TP63 gene generates six major protein isoforms through the use of two alternative promoters and C-terminal alternative splicing. The TAp63 isoforms (TAp63α, TAp63β, and TAp63γ) are transcribed from an upstream promoter and include a full-length N-terminal transactivation (TA) domain, enabling sequence-specific transcriptional activation. In contrast, the ΔNp63 isoforms (ΔNp63α, ΔNp63β, and ΔNp63γ) arise from a downstream promoter, resulting in a truncated N-terminus that lacks the TA domain but can function as a dominant-negative regulator of TAp63 or p53 activity, or act independently as a transcriptional activator depending on context.) All p63 isoforms share a conserved core structure, including a proline-rich (PRD, residues ~67–127) that mediates protein-protein interactions via PXXP , a central (DBD) with ~65% to that recognizes consensus DNA sequences through a loop-sheet-helix , and an oligomerization (OD) that assembles into tetramers as dimers of dimers, stabilized by a C-terminal α-helix. The C-termini vary by splicing: α isoforms (~680 for TAp63α) include a sterile alpha (SAM) domain forming a five-helix bundle and a transactivation inhibitory (TID, residues ~597–614) that is intrinsically disordered but adopts a β-strand in autoinhibited states; β isoforms (~637 ) lack SAM and TID; and γ isoforms (~642 ) feature a unique 38-residue extension after the OD. Additional variants like TA*p63α include an N-terminal extension of 39 residues for enhanced dimer stability.) Post-2020 structural analyses have advanced understanding of p63 architectures and interactions. High-resolution studies, including NMR and modeling, have detailed the intrinsically unfolded TA domain forming a single long (residues 8–25) and the autoinhibitory dimer conformation of TAp63α, where TID masks the TA domain. The DBD-DNA complex structures reveal specific binding to 10–22 bp sequences, while tetramerization mechanisms highlight isoform-specific oligomer states, with ΔNp63 favoring constitutive tetramers and TAp63 forming inactive dimers.

Biological Functions

Developmental Roles in Epithelia and Limbs

p63 plays a pivotal role in embryonic , particularly in the formation and of epithelial tissues and the of limbs. In mice lacking p63, profound defects are observed, including the failure to develop stratified squamous epithelia, resulting in thin, undifferentiated skin resembling , and severe limb truncations due to impaired ectodermal signaling and progenitor . These phenotypes highlight p63's necessity in preventing ectodermal dysplasia-like abnormalities during embryogenesis, as p63-null embryos exhibit craniofacial malformations alongside the epithelial and limb issues. In epithelial development, p63 orchestrates the transition from single-layered to multilayered stratified epithelia, such as the . The ΔNp63 isoform predominates in early stages, driving basal and commitment to the epidermal lineage by maintaining potential and suppressing alternative fates. As stratification progresses, TAp63 becomes more prominent, facilitating and to activate genes involved in barrier formation. Recent studies emphasize how p63 isoforms coordinate accessibility in developing tissues, including limb buds, where they recruit factors like complexes to enhancers, enabling ectodermal essential for appendage outgrowth. p63 also mediates critical epithelial-mesenchymal interactions that underpin limb and craniofacial development. In limb buds, p63 expression in the apical ectodermal ridge (AER) regulates downstream targets such as Fgf8, which sustains mesenchymal proliferation and proximal-distal patterning; without p63, AER formation fails, leading to truncated appendages. Similarly, p63 directly binds and activates IRF6, a that modulates epithelial integrity and mesenchymal signaling during palatal shelf fusion and facial . In craniofacial structures, p63 targets like PERP contribute to epithelial and , ensuring proper shelf elevation and fusion to avert developmental clefts. These interactions underscore p63's role as a hub integrating signaling pathways like FGF and to coordinate ectoderm-derived tissue architecture.

Maintenance of Tissue Homeostasis and Stem Cells

The ΔNp63 isoform of p63 serves as a critical for maintenance in stratified epithelia, particularly in the basal layers of and , where it drives and prevents premature differentiation.00384-4) In these tissues, ΔNp63 directly or indirectly upregulates genes encoding basal keratins such as KRT5 and KRT14, which are essential for cytoskeletal integrity and the migratory capacity of proliferating basal cells. Loss of ΔNp63 in these compartments impairs clonogenic potential, leading to reduced epithelial renewal and exhaustion.00384-4) In hair follicles and the , ΔNp63 coordinates the balance between self-renewal and differentiation of epithelial stem cells, ensuring tissue regeneration throughout adulthood. These stem cell populations, which originate from embryonic progenitors committed during , rely on ΔNp63 to sustain bulge or basal niches where transient amplifying cells replenish differentiated layers. of p63 disrupts this equilibrium, resulting in defective hair cycling, loss of follicle integrity, and diminished prostate gland , with long-term consequences including aging-associated defects such as epidermal thinning and reduced regenerative capacity. For instance, p63-deficient exhibit accelerated markers, contributing to organismal aging phenotypes in stratified epithelia. Recent studies have highlighted p63's role in suppressing epithelial-to-mesenchymal transition (EMT) to preserve tissue homeostasis, particularly through ΔNp63-mediated repression of EMT inducers like ZEB1 and SNAI1 in basal epithelial cells. This anti-EMT function is vital for maintaining epithelial integrity and preventing pathological remodeling in adult tissues. ΔNp63 integrates with signaling pathways such as Notch and Wnt to reinforce basal cell identity and proliferative competence. Wnt/β-catenin signaling activates ΔNp63 expression in basal progenitors, promoting self-renewal while inhibiting differentiation programs, whereas Notch signaling antagonizes p63 to favor commitment to differentiated states in suprabasal layers. This cross-talk ensures precise spatiotemporal control of epithelial homeostasis, with disruptions leading to imbalances in stem cell dynamics.

Reproductive and Oocyte-Specific Functions

The TAp63 isoform, the primary p63 variant expressed in the nuclei of oocytes within primordial follicles, plays a pivotal role in safeguarding female integrity by inducing in response to DNA damage during I arrest of . This process eliminates irreparably damaged oocytes, thereby preserving the and averting the transmission of genomic instability to future generations, which could otherwise lead to . Activation of TAp63 occurs through by DNA damage response kinases such as , prompting its tetramerization and subsequent transcription of pro-apoptotic effectors like and NOXA.00735-6) In addition to its pro-apoptotic functions, TAp63 contributes to the regulation of pathways in primordial follicles, including the expression of genes involved in such as and , ensuring timely resolution of double-strand breaks to maintain viability. Deficiency in p63, as observed in models, leads to the persistence of DNA-damaged oocytes by preventing their apoptotic elimination, thereby preserving the follicular pool under genotoxic stress but potentially risking the transmission of genomic instability. Recent single-cell transcriptional analyses have further elucidated how TAp63 orchestrates both pro-survival responses and apoptotic elimination in oocytes under genotoxic stress, highlighting its dual role in genomic maintenance. In humans, germline mutations in TP63, particularly gain-of-function variants in the TAp63 isoform, are associated with ovarian dysgenesis and premature ovarian insufficiency, underscoring its conserved function in reproductive health. These mutations hyperactivate apoptotic pathways in s, resulting in reduced follicle numbers and . Complementing these findings, 2024 investigations into oocyte chromatin dynamics have revealed p63's involvement in remodeling architecture to facilitate foci formation and enhance genomic stability during meiotic arrest, preventing and age-related oocyte attrition.01281-8)

Molecular Mechanisms

Transcriptional Regulation by p63

p63 functions as a sequence-specific transcription factor, primarily binding to DNA through its DNA-binding domain (DBD), which recognizes p53-responsive elements characterized by the consensus sequence RRRCWWGYYY, where R denotes A or G, W denotes A or T, and Y denotes C or T. This binding is facilitated by the formation of tetramers, which enhance DNA affinity and stability, particularly for the TAp63α isoform upon activation. The DBD shares high structural similarity with that of p53, enabling p63 to target overlapping response elements while exhibiting some degeneracy in sequence preferences. The (TA) isoforms, such as TAp63, promote the expression of genes involved in epithelial , including keratin 1 (KRT1), a marker of early , and interferon regulatory factor 6 (IRF6), which supports craniofacial and skin development. In contrast, the ΔN isoforms, notably ΔNp63, lack the TA domain and often act as repressors by exerting a dominant-negative effect on and TAp63, inhibiting the transcription of shared targets such as regulators. This repression occurs through competitive binding to response elements or interference with family tetramerization, thereby maintaining states in stratified epithelia. p63's transcriptional activity is highly context-dependent, with genome-wide studies in identifying over 3,000 direct target genes associated with its binding sites, influencing processes like control via CDKN1A (encoding p21) and through PERP. These targets underscore p63's dual role in and , where binding efficiency can vary slightly among isoforms due to differences in their transactivation potentials. In cancer contexts, recent investigations have highlighted p63's involvement in thyroid carcinoma progression, where it upregulates keratin 17 (KRT17) expression, promoting epithelial-mesenchymal transition and tumor invasiveness.

Chromatin Remodeling and Enhancer Interactions

p63 plays a pivotal role in orchestrating chromatin remodeling by recruiting the insulator protein CTCF and the cohesin complex to establish topologically associating domains (TADs) and enhancer-promoter interactions in keratinocytes. In skin keratinocytes, p63 binds to distal enhancers, while CTCF predominantly occupies promoters and TAD boundaries, facilitating the formation of chromatin loops that connect regulatory elements to target genes involved in epidermal differentiation, such as KRT5 and PIGV. These loops, with a median size of approximately 251 kb, enable precise spatial organization of the genome, promoting the accessibility of squamous-specific loci and maintaining epithelial identity. Recent analyses have shown that p63-bound regions exhibit enriched CTCF and cohesin occupancy, underscoring p63's function in stabilizing higher-order chromatin structures essential for tissue-specific gene regulation. Mutations in TP63, particularly those associated with ectrodactyly-ectodermal dysplasia-cleft (EEC), disrupt these enhancer loops, resulting in misregulated expression of squamous genes. For instance, EEC like R204W and R304W impair p63's DNA-binding affinity, leading to reduced accessibility at 2,492 control-specific open regions and aberrant opening of 3,716 mutant-specific regions, which deregulate 39 co-targeted genes and compromise epidermal . These disruptions exemplify p63's necessity in preserving loop integrity for proper squamous gene networks. p63 cooperates with epigenetic modifiers, including histone deacetylases (HDACs) such as and HDAC2, to modulate acetylation at enhancers, thereby fine-tuning states for transcriptional control. ΔNp63α recruits /2 to enhancer regions of target genes like , promoting deacetylation of H4 and repressing anti-proliferative programs in . This interaction allows p63 to balance activation and repression, as evidenced by cell-type-specific variations where HDAC recruitment enhances compaction at select enhancers. Complementing this, p63 engages histone acetyltransferases like p300 to acetylate at active enhancers, fostering open conformations. Emerging 2025 research elucidates p63-mediated enhancements in accessibility at developmental hubs, positioning p63 as a pioneer factor that initiates remodeling in epidermal progenitors. By binding closed and recruiting complexes (e.g., Brg1) alongside p300, p63 increases accessibility at enhancer clusters within loci like the epidermal complex, facilitating nuclear repositioning and loop formation for lineage commitment. In models, p63 drives compartment switching from B to A, enriching keratinization pathways and underscoring its role in developmental chromatin hubs. These findings highlight p63's integration of 3D with accessibility to sustain epithelial .

Disease Associations

Germline Mutations and Associated Syndromes

Germline mutations in the TP63 gene, located on chromosome 3q28 (OMIM #603273), are heterozygous and primarily missense variants that disrupt the protein's function, leading to a spectrum of autosomal dominant developmental disorders characterized by , limb malformations, and orofacial clefting. Over 40 such pathogenic germline mutations have been identified, with the majority being missense changes clustered in the (DBD) or the sterile alpha motif () domain, though frameshift and nonsense variants also occur in the C-terminal regions. These mutations interfere with p63's essential roles in epithelial and limb development, resulting in impaired tissue differentiation and morphogenesis. The most prominent syndromes associated with TP63 germline mutations include ectrodactyly-ectodermal dysplasia-cleft lip/palate syndrome type 3 (EEC3; OMIM #604292), (SHFM4; OMIM #605289), and ankyloblepharon-ectodermal defects-cleft lip/palate syndrome (Hay-Wells or AEC syndrome; OMIM #106260). EEC3, the most common, features bilateral (lobster-claw-like limb defects), (sparse hair, reduced sweating, and dental anomalies), and cleft lip with or without palate, often accompanied by genitourinary tract abnormalities. SHFM4 primarily manifests as isolated or severe split hand/foot malformations without prominent ectodermal features, though some overlap with EEC3 phenotypes occurs. Hay-Wells syndrome is distinguished by ankyloblepharon filiforme adnatum (adherent eyelids), severe ectodermal defects including scalp erosions and nail dystrophy, and frequent cleft palate, with a higher risk of recurrent infections due to epidermal barrier issues. These syndromes collectively affect multiple ectoderm-derived structures, with variable expressivity even within families. Genotype-phenotype correlations are well-established for TP63 mutations, guiding clinical anticipation. Missense mutations in the DBD, such as R204W, R227Q, and R279H, predominantly cause EEC3 or SHFM4 by impairing DNA binding and transcriptional activation, leading to milder ectodermal involvement compared to other domains. In contrast, mutations in the SAM domain, exemplified by L514F and I529T, are characteristic of Hay-Wells syndrome, where they disrupt protein oligomerization and result in more severe ectodermal dysplasia and erosive skin lesions. Frameshift or nonsense mutations truncating the transactivation inhibitory domain (TID) are linked to limb-mammary syndrome (LMS; OMIM #603543) or premature ovarian failure type 21 (POF21; OMIM #620311), highlighting domain-specific impacts on reproductive and mammary development. EEC3 has an estimated prevalence of 1-9 per 100,000 individuals, making it a rare disorder, while the overall incidence of TP63-related syndromes remains low due to their origin in approximately 70% of cases. Ongoing molecular studies continue to refine these associations, emphasizing the gene's critical role in ectodermal .

Somatic Alterations and Role in Cancer

Somatic alterations in the TP63 , particularly and overexpression of the ΔNp63 isoform, are common in various epithelial cancers and contribute to tumorigenesis by dysregulating normal homeostatic functions in tissues such as stratified epithelia. In squamous cell carcinomas (SCCs), ΔNp63 drives oncogenic signaling, including enhanced and resistance to , by acting as a dominant-negative regulator of family members.30561-X.pdf) This alteration is frequently observed across multiple SCC subtypes, where it promotes tumor initiation and progression through interactions with remodelers and super-enhancers. In head and neck squamous cell carcinomas (HNSCC), ΔNp63 is amplified in approximately 30% of cases and overexpressed in up to 80% of primary tumors, correlating with poor prognosis and increased metastatic potential.00394-6.pdf) Similarly, in lung squamous cell carcinoma, genomic amplification of TP63 occurs in about 88% of cases, often early in tumorigenesis, and supports anchorage-independent growth by upregulating metabolism genes. In skin SCC, p63 overexpression is prevalent and contributes to tumor expansion by maintaining stem-like properties in cancer cells. In vulvar , hypermethylation of the IRF6 promoter leads to inactivation of this , which is transactivated by p63, thereby promoting disease progression from lichen sclerosus-associated lesions. This epigenetic alteration dysregulates p63-dependent pathways, enhancing invasive potential in vulvar tumors. TP63 plays a role in prostate cancer by enabling evasion of oncogene-induced , where ΔNp63 overexpression sustains in basal-like tumor cells and inhibits p53-mediated arrest. In , TP63 upregulates KRT17 expression, inducing epithelial-mesenchymal transition and facilitating malignant progression. Recent studies highlight TP63's involvement in regulating , a form of inflammatory , in tumors, influencing immune evasion mechanisms from 2022 to 2025. In and other cancers, TP63 modulates pyroptosis-related genes via pathways, with high TP63 expression correlating with altered immune infiltration and reduced antitumor immunity in the . In SCC, TP63 overexpression inhibits activity, suppressing responses and promoting immune escape.

Diagnostic and Therapeutic Implications

Diagnostic Applications in Pathology

In pathology, p63 serves as a key immunohistochemical (IHC) due to its nuclear expression in basal and myoepithelial cells of various epithelia, aiding in the differentiation of benign from malignant lesions and specific tumor types. In normal and tissues, p63 exhibits strong nuclear staining in basal cells, which is typically absent in invasive , allowing pathologists to confirm the presence of an intact basal layer in or atypical intraductal proliferations. This pattern helps distinguish prostatic from mimics, with p63 demonstrating high sensitivity (approximately 90-98%) and specificity (96-100%) for basal cell identification in biopsies. p63 IHC is particularly valuable in diagnosing squamous cell carcinomas (SCCs), where it shows positivity in 90-100% of cases across various sites, including , , and , contrasting with negativity in most mimics. For instance, in pulmonary non-small cell carcinomas, p63 positivity supports SCC over , though p40 (a p63 isoform) offers even higher specificity in this context. In cutaneous lesions, p63 aids in confirming SCC versus or metastatic , with strong diffuse nuclear staining in the majority of SCCs. Diagnostic panels incorporating p63 enhance accuracy in challenging cases, such as distinguishing prostate adenocarcinoma from urothelial carcinoma. Combining p63 with cytokeratin 5/6 (CK5/6) highlights basal/myoepithelial cells in prostate lesions while CK5/6 positivity in tumor cells favors urothelial origin, improving lineage determination in biopsies. This approach is especially useful in high-grade or poorly differentiated tumors where morphology alone is inconclusive. Beyond IHC, next-generation sequencing (NGS) has emerged as a diagnostic tool for detecting TP63 germline variants in syndromes featuring cleft lip/palate, such as EEC syndrome. Recent 2024 studies using targeted NGS panels have identified novel TP63 variants in affected families, enabling precise molecular diagnosis and for these overlapping phenotypes.

Therapeutic Targeting and Potential Strategies

Therapeutic strategies targeting TP63 focus on modulating p63 function in cancers and genetic syndromes associated with its mutations, leveraging s, isoform-specific interventions, gene editing, and epigenetic modulators. In cancers harboring mutant , which can inhibit wild-type p63 activity, the APR-246 (also known as PRIMA-1MET or eprenetapopt) restores conformational stability to mutant p53 family members, including p63, thereby reactivating p63-dependent transcriptional programs that promote and inhibit tumor growth. This compound has demonstrated efficacy in preclinical models of lung cancer and epidermal differentiation defects by enhancing p63 DNA binding and target . Although a III clinical trial in combination with for TP53-mutated myelodysplastic syndromes failed to meet its primary endpoint in 2021, and as of 2025, no ongoing s are reported, preclinical evidence suggests potential for p63-relevant solid tumors due to its family-wide effects. For the oncogenic ΔNp63 isoform prevalent in squamous cell carcinomas, preclinical efforts emphasize targeted degradation to disrupt tumor maintenance. Inhibition of the deubiquitinase USP28 destabilizes ΔNp63 by preventing its stabilization, leading to reduced proliferation in squamous tumor models such as head and neck and lung cancers. This approach exploits the ubiquitin-proteasome pathway, where USP28 normally counteracts APC/C-mediated degradation of ΔNp63 during mitosis, and its blockade induces proteasomal turnover, suppressing squamous cell carcinoma growth in vitro and in vivo. Recent preclinical studies, including 2024 data demonstrating that USP28 inhibition sensitizes squamous cell carcinomas to cisplatin by destabilizing ΔNp63, highlight the potential of such degraders in isoform-specific targeting, building on observations that ΔNp63 overexpression drives epithelial proliferation and resistance in these malignancies. In germline syndromes like ectrodactyly-ectodermal dysplasia-clefting (EEC), using /Cas systems offers proof-of-concept for correcting TP63 mutations. Allele-specific editing, including Cpf1-based approaches, has been developed to selectively disrupt dominant-negative mutant TP63 alleles in EEC patient-derived , restoring wild-type p63 function and epithelial without off-target effects on the healthy allele. A 2024 initiative demonstrated feasibility in ocular surface disorder models of EEC, where editing alleviated mutation-induced defects and improved cellular phenotypes, paving the way for therapies. Combination therapies exploiting p63's epigenetic interactions show promise in specific cancers, such as vulvar . (HDAC) inhibitors disrupt the physical association between ΔNp63 and /2, which normally maintains repressive states at pro-apoptotic genes like , leading to derepression, increased , and selective tumor in squamous models. In vulvar , where class I HDACs are overexpressed and correlate with poor , combining HDAC inhibitors like with standard chemotherapies enhances by altering p63- dynamics and sensitizing cells to . This strategy leverages p63's role in somatic alterations driving squamous oncogenesis, offering a targeted means to overcome resistance.

Protein Interactions

Direct Physical Interactors

The p63 protein, a member of the family of transcription factors, engages in direct physical interactions with several proteins that facilitate its roles in gene regulation and cellular processes. One key interactor is heterogeneous nuclear ribonucleoprotein A/B (HNRNPAB, also known as ABBP1), which binds to the C-terminal sterile alpha (SAM) domain of p63α, a region adjacent to its proline-rich domain (PRD). This interaction supports alternative mRNA splicing, particularly of the (FGFR2) transcript, promoting the epithelial-specific K-SAM isoform essential for differentiation. Disruptions in this binding, such as those caused by mutations in the SAM domain associated with ankyloblepharon-ectodermal defects-cleft lip/palate () syndrome, lead to aberrant splicing patterns. While primarily linked to splicing regulation, the p63-HNRNPAB complex indirectly influences mRNA stability and localization by modulating post-transcriptional processing in epithelial cells. p63 forms heterodimers and heterotetramers with its family members and p73, primarily through the oligomerization domain (), which enables cooperative DNA binding and transcriptional activity. The interaction with p73 is particularly robust, forming stable p63₂/p73₂ heterotetramers that enhance transcriptional potency in epithelial tissues compared to homotetramers. This heterodimerization has been confirmed by co-immunoprecipitation (co-IP) assays in , demonstrating physical association under physiological conditions, and yeast two-hybrid screening, which identified direct OD-mediated contacts. Recent structural studies in 2023 provide high-resolution evidence via (PDB: 8P9D), revealing hydrophobic interfaces in the OD that stabilize the p63-p73 heterotetramer. Interactions with are weaker and less frequent, often requiring specific isoforms, but similarly rely on OD homology to modulate p53 family dynamics. These structural domains, including the OD's tetramerization unique to p63 and p73, underpin the specificity of these partnerships. Another interactor is , which cooperates with p63 to organize architecture at enhancer-promoter loops in epithelial cells. This cooperation facilitates CTCF's role as a anchor by involving p63 in loop boundaries. This interaction is crucial for establishing tissue-specific conformations, such as those regulating epidermal differentiation genes, without relying solely on shared DNA motifs.

Functional and Pathway Interactions

p63 plays a pivotal role in ectodermal development by directly activating IRF6 transcription through binding to an enhancer element approximately 10 kb upstream of the IRF6 transcription start site. This interaction, identified via ChIP-seq and confirmed by ChIP-qPCR, ensures robust IRF6 expression, which is critical for epithelial differentiation and preventing developmental anomalies such as cleft palate. Disruptions in this p63-IRF6 regulatory feedback loop, including mutations in either gene, lead to ectodermal dysplasias, as evidenced by compound heterozygous models exhibiting cleft palate in approximately 89% of embryos. In the DNA damage response pathway, integrates with and to promote following genotoxic stress. kinase phosphorylates ΔNp63α, triggering its ubiquitin-mediated degradation and thereby alleviating repression of proapoptotic genes, which enhances -dependent . Similarly, and p73 are required for efficient -induced , as their combined impairs this response despite intact function, underscoring 's role in coordinating repair and elimination of damaged cells. This -- axis maintains genomic stability, with evidence from models showing reduced in p63/p73-deficient cells exposed to DNA-damaging agents. p63 engages in crosstalk with Notch and Wnt signaling pathways within stem cell niches, particularly in epidermal and mammary contexts, to regulate self-renewal and differentiation. In skin stem cell niches, p63 inhibits Notch1 activity by suppressing its target HES1, thereby maintaining quiescence and stemness of keratinocytes and hair follicle stem cells through enhanced integrin expression (e.g., α3β1, α6β4) for basement membrane attachment. This antagonistic interaction forms a negative feedback loop, where Notch signaling downregulates p63 via IRF3/7 and IRF6, promoting differentiation markers like keratin 1/10 and p21. Concurrently, p63 represses Wnt/β-catenin signaling in keratinocyte stem cells by associating with TCF4 at Wnt response elements, reducing β-catenin recruitment and target gene expression (e.g., AXIN2, MMP7), which prevents excessive proliferation and supports epithelial homeostasis. p63 suppresses epithelial-mesenchymal transition () through interactions that target ZEB1, a key EMT inducer. The ΔNp63α isoform promotes transcription of miR-205 by binding upstream of its host gene promoter, recruiting and elevating miR-205 levels, which in turn directly repress ZEB1 and ZEB2 expression to maintain epithelial integrity in and other epithelial cancers. Loss of ΔNp63α increases ZEB1/2 and enhances invasion, while miR-205 restoration reverses this, highlighting p63's role in preventing metastatic progression via this microRNA-mediated axis.

Regulation of TP63

Transcriptional and Epigenetic Control

The TP63 gene employs two distinct promoters to produce its primary isoforms, enabling context-specific regulation of epithelial development and . The upstream P1 promoter, a TATA-less sequence located in the , drives transcription of the full-length TAp63 isoforms, which include a p53-like essential for tumor suppressor functions. In contrast, the internal P2 promoter, situated within 3, initiates expression of the N-terminally truncated ΔNp63 isoforms, which lack the canonical but utilize an alternative truncated version to promote and squamous . This dual-promoter architecture allows for differential isoform abundance across cell types, with ΔNp63 predominating in basal epithelia. Epigenetic modifications at the TP63 locus fine-tune its expression in a - and -dependent manner. Active enhancers near the ΔNp63 transcription start site exhibit enrichment of lysine 27 (H3K27ac), marking open accessible to transcriptional machinery in squamous epithelial cells. This H3K27ac landscape supports enhancer-promoter interactions that sustain high TP63 levels in stratified epithelia, such as and , while repressive marks imposed by silence TP63 in non-epithelial lineages like neuroendocrine cells. In differentiated , microRNA-203 (miR-203) directly represses ΔNp63 by binding its 3' , thereby limiting proliferative potential and promoting terminal . Recent analyses confirm these dynamics, showing inhibition increases H3K27ac at TP63 enhancers, derepressing ΔNp63 to reinforce squamous identity over neuroendocrine . A 2025 study identified TP63 as a mediator of tumor-specific loops via new accessible sites, enhancing enhancer-promoter interactions in cancer contexts. Transcription factors, particularly those activated during , further modulate TP63 expression to adapt to environmental cues. directly binds the TAp63 promoter, inducing its transcription in response to proinflammatory signals like TNF-α, thereby linking immune activation to epithelial repair and survival. Similarly, AP-1 family members, responsive to growth factors such as EGF and TGFβ, cooperate in orchestrating TP63 upregulation during inflammatory states, enhancing squamous epithelial resilience. Tissue-specific patterns underscore this regulation: TP63 transcripts are highly abundant in epithelial tissues like , , and , where they maintain pools, but remain low or absent in neuronal tissues, reflecting restricted roles outside stratified structures. 2024 studies on esophageal squamous tissues highlight super-enhancer-like H3K27ac clusters at the TP63 locus, amplifying expression in inflammation-prone environments and underscoring their role in lineage fidelity.

Post-Translational Modifications

Post-translational modifications of the p63 protein significantly influence its stability, transcriptional activity, and cellular functions, with key modifications occurring on specific domains such as the transactivation (TA) domain and sterile alpha motif (SAM) domain. Phosphorylation of p63 occurs primarily in response to DNA damage and targets sites within the TA domain of TAp63 isoforms. Specifically, upon DNA damage, checkpoint kinase 2 (CHK2) acts as a priming kinase to phosphorylate TAp63 at serine 582, enabling subsequent phosphorylation by casein kinase 1 (CK1) at four consecutive sites (serines 585, 588, 591, and threonine 594), which collectively activate p63's transcriptional activity and promote apoptosis in contexts like oocyte quality control. This multi-site phosphorylation cascade enhances p63's ability to induce target genes involved in cell fate decisions. Ubiquitination regulates p63 protein levels through proteasome-mediated , with distinct enzymes targeting different isoforms. The deubiquitinase USP28 stabilizes the ΔNp63 isoform prevalent in squamous cell carcinomas by deubiquitinating K48-linked chains, thereby counteracting and maintaining high ΔNp63 levels essential for tumor maintenance. Conversely, the E3 Itch promotes the ubiquitination and proteasomal of p63α isoforms, particularly during , where Itch binds to the C-terminal region of p63 to reduce its steady-state levels and facilitate epithelial maturation. Acetylation by the p300 modulates p63's transcriptional potency, particularly for the p63γ isoform. p300 interacts with and p63 at residues, enhancing its ability to activate target genes without affecting protein stability, as demonstrated and in cellular assays where p300 co-expression boosts p63γ-driven transcription. This modification distinguishes p63 regulation from that of , where acetylation also influences stability. Sumoylation specifically targets the α isoforms of p63 at lysine 637 in the post-SAM domain, altering protein and function. Conjugation of SUMO-1 to this site increases p63α's transcriptional activity and by preventing ubiquitination and degradation, without impacting subcellular localization. This modification is absent in β and γ isoforms, highlighting isoform-specific regulation of p63's role in epithelial development and .

References

  1. [1]
    TP63 gene: MedlinePlus Genetics
    ### Summary of TP63 Gene
  2. [2]
  3. [3]
    8626 - Gene ResultTP63 tumor protein p63 [ (human)] - NCBI
    Sep 27, 2025 · TP63 encodes a transcription factor in the p53 family, involved in skin development, stem cell regulation, and heart development. Mutations are ...
  4. [4]
    p63: A Master Regulator at the Crossroads Between Development ...
    Jan 3, 2025 · The p63 protein is a master regulatory transcription factor that plays crucial roles in cell differentiation, adult tissue homeostasis, and chromatin ...
  5. [5]
    TP63-Related Disorders - GeneReviews® - NCBI Bookshelf - NIH
    Jun 8, 2010 · TP63-related disorders include six overlapping phenotypes: AEC, ADULT, EEC3, Limb-mammary, SHFM4, and isolated cleft lip/cleft palate.
  6. [6]
    The dual role of p63 in cancer - PMC - PubMed Central - NIH
    Apr 27, 2023 · TAp63 (a subtype of p63), widely known as a synergistic effector with p53, promotes cancer cell apoptosis after chemotherapy and is involved in ...
  7. [7]
    Role of p63 in Development, Tumorigenesis and Cancer Progression
    In contrast to p53, the TP63 gene is rarely mutated in human cancers [12, 79, 80]. Rather, ΔNp63α is often over-expressed in low-grade squamous cell carcinoma ( ...
  8. [8]
    Loss of TP63 promotes the metastasis of head and neck squamous ...
    However, whether TP63 functions as a tumor promoter or a tumor suppressor has remained controversial. A role for TP63 in tumor promotion has been suggested ...
  9. [9]
  10. [10]
    The Rapp–Hodgkin syndrome results from mutations of the TP63 gene
    Aug 26, 2003 · Indeed, the TP63 gene, composed of 16 exons (Figure 1a), encodes six main isoforms (Figure 1b). The usage of an alternative promoter results in ...
  11. [11]
    Structural evolution of p53, p63, and p73: Implication for ... - PNAS
    Oct 20, 2009 · Implications for the Evolution of the p53 Family. It is generally believed that p63 and p73 more closely resemble the common ancestral ...
  12. [12]
    The Origins and Evolution of the p53 Family of Genes - PMC
    A common ancestor to the three p53 family members of human genes p53, p63, and p73 is first detected in the evolution of modern‐day sea anemones.
  13. [13]
    Structural diversity of p63 and p73 isoforms - Nature
    Mar 21, 2022 · Here we review the structure and organization of the individual domains of p63 and p73, the interaction of these domains in the context of full-length proteins.
  14. [14]
    The proline-rich domain in p63 is necessary for the transcriptional ...
    We discovered that both the activation domain (residues 1-59) and the proline-rich domain (residues 67-127) are required for TAp63 transcriptional activity.
  15. [15]
    p63 is a p53 homologue required for limb and epidermal ... - PubMed
    Mice lacking p63 are born alive but have striking developmental defects. Their limbs are absent or truncated, defects that are caused by a failure of the apical ...Missing: knockout | Show results with:knockout
  16. [16]
    ΔNp63 Is Essential for Epidermal Commitment of Embryonic Stem ...
    ΔNp63 gene expression remains high during epithelial development. P63 loss of function drastically prevents ectodermal cells to commit to the K5/K14-positive ...
  17. [17]
    p63: a crucial player in epithelial stemness regulation | Oncogene
    Oct 17, 2023 · Its encoding gene TP63 generates two main classes of isoforms by the usage of alternative promoters. ... Altogether, the TP63 gene expresses at ...
  18. [18]
    p63 cooperates with CTCF to modulate chromatin architecture in ...
    Jun 4, 2019 · Our study suggests an intriguing model where cell type-specific transcription factors such as p63 cooperate with the genome organizer CTCF in the three- ...Missing: buds | Show results with:buds
  19. [19]
    An etiologic regulatory mutation in IRF6 with loss- and gain-of ... - NIH
    In sum, these data provide strong evidence that p63 regulates IRF6 expression by directly binding to two neighboring sites within MCS9.7. While mutations in ...
  20. [20]
    Differential PERP regulation by TP63 mutants provides insight into ...
    Apr 7, 2009 · ... Cleft Lip/Palate (AEC) or Hay–Wells ... p63 is essential for regenerative proliferation in limb, craniofacial and epithelial development.
  21. [21]
    Facial clefting in Tp63 deficient mice results from altered Bmp4, Fgf8 ...
    Our results are consistent with a role for Tp63 in the regulation of Bmp signaling controlling the growth, modelling and fusion events underlying facial ...
  22. [22]
    p63 and the epithelial stem cell: more than status quo?
    This unprecedented phenotype underscored the significance of p63 in epithelial morphogenesis, but demanded considerable forensic analysis to determine what went ...
  23. [23]
    p63 deficiency activates a program of cellular senescence and leads ...
    We demonstrate that cellular senescence and organismal aging are intimately linked and that these processes are mediated by p63 loss.
  24. [24]
    ΔN-Tp63 Mediates Wnt/β-Catenin-Induced Inhibition of ...
    Sep 24, 2019 · In Basal cells, Wnt prevents specification of epithelial cell types by activating ΔN-TP63, a master transcription factor, which is necessary and ...
  25. [25]
    Cross-regulation between Notch and p63 in keratinocyte ...
    Here we show that p63 expression is suppressed by Notch1 activation in both mouse and human keratinocytes through a mechanism independent of cell cycle ...
  26. [26]
    Oocyte death is triggered by the stabilization of TAp63α dimers in ...
    Nov 7, 2024 · Our study reveals a novel mechanism of cisplatin-induced apoptosis in primordial follicle oocyte through TAp63α stabilization and accumulation, independent of ...Results · Cddp Induces Tap63α... · Cddp-Induced Oocyte...
  27. [27]
    Single-cell and bulk transcriptional profiling of mouse ovaries ...
    TAp63 and p53 activate both pro-apoptotic and pro-survival responses in oocytes. Abstract. Immature oocytes enclosed in primordial follicles stored in female ...<|separator|>
  28. [28]
    Oocytes can efficiently repair DNA double-strand breaks to ... - PNAS
    May 7, 2020 · We show that when apoptosis is inhibited, oocytes can repair severe DNA damage via homologous recombination repair. The repair is highly efficient.Oocyte And Embryo Collection · Treatment Of Tap63 Mice With... · ResultsMissing: isoform | Show results with:isoform
  29. [29]
    TP63 gain-of-function mutations cause premature ovarian ... - NIH
    Mar 1, 2023 · R643Q mutation in TP63 was fertile (Supplemental Figure 1B). These results indicate that the TID-related mutations in TP63 might only affect ...
  30. [30]
    TP63 truncating mutation causes increased cell apoptosis and ...
    Mar 25, 2024 · Genetic mutations are important factors causing POI. TP63-truncating mutation has been reported to cause POI by increasing germ cell apoptosis, ...
  31. [31]
    Derivation of the consensus DNA-binding sequence for p63 reveals ...
    Aug 7, 2006 · Our analysis shows that the optimal p63 DNA-binding consensus motif consists of a CA(T)TG core and an AT-rich 5' and 3' flanking sequence.
  32. [32]
    REDD1, a Developmentally Regulated Transcriptional Target of p63 ...
    REDD1 encodes a shared transcriptional target that implicates ROS in the p53-dependent DNA damage response and in p63-mediated regulation of epithelial ...
  33. [33]
    Solution structure and binding specificity of the p63 DNA ... - Nature
    May 26, 2016 · The high level of sequence similarity in the DNA binding domain (DBD) allows p63 and p73 to trans-activate p53-responsive genes resulting in ...
  34. [34]
    Cooperation between the transcription factors p63 and IRF6 is ...
    Apr 26, 2010 · Furthermore, we showed that p63 transactivated IRF6 by binding to an upstream enhancer element; genetic variation within this enhancer element ...Missing: KRT1 | Show results with:KRT1
  35. [35]
    ΔNp63α represses anti-proliferative genes via H2A.Z deposition - PMC
    Oct 15, 2012 · Because ΔNp63α and p53 bind virtually identical DNA sequence motifs, it has been proposed that ΔNp63α functions as a dominant-negative inhibitor ...
  36. [36]
    p63 and p53: Collaborative Partners or Dueling Rivals? - Frontiers
    Jul 4, 2021 · The p53 transcription factor family comprises the three members p53, p63, and p73. Although it is evolutionarily the youngest, p53 is the ...
  37. [37]
    Role of chromatin and transcriptional co-regulators in mediating p63 ...
    Nov 29, 2014 · The Transcription Factor (TF) p63 is a master regulator of epidermal development and differentiation as evident from the remarkable skin ...
  38. [38]
    Genome-Wide Profiling of p63 DNA–Binding Sites Identifies an ...
    In summary, we have identified binding sites of p63 and taken the first step to build a gene network regulated by p63 with ChIP-seq analysis in human primary ...
  39. [39]
    Transcription factors TP63 facilitates malignant progression of ...
    Mar 15, 2023 · All these results verified that TP63 facilitates TC malignant progression by promoting KRT17 expression and inducing EMT.Missing: p63 2025
  40. [40]
    p63 cooperates with CTCF to modulate chromatin architecture ... - NIH
    Jun 4, 2019 · In control keratinocytes, a total of 1223 p63 binding sites (BSs) were covered by the 2492 Ctr-OCRs, showing a significant overlap (p < 0.001).
  41. [41]
    TP63 links chromatin remodeling and enhancer reprogramming to ...
    TP63 is a master regulator that plays an essential role in epidermal differentiation. It is also a lineage-dependent oncogene in SCC.
  42. [42]
    ΔNp63α utilizes multiple mechanisms to repress transcription ... - NIH
    As HDAC recruitment and histone acetylation at select p53/p63/p73 enhancer sites regulate gene expression and proliferation in keratinocytes and JHU-029 cells, ...
  43. [43]
    TP63 mediates the generation of tumour-specific chromatin loops ...
    Sep 30, 2025 · ... TP63 peaks is associated with increased CTCF and cohesin ... p63 cooperates with CTCF to modulate chromatin architecture in skin keratinocytes.Missing: remodeling | Show results with:remodeling
  44. [44]
    Entry - *603273 - TUMOR PROTEIN p63; TP63 - OMIM - (OMIM.ORG)
    TP63, also known as TUMOR PROTEIN p63, is located at 3q28 and is also known as TUMOR PROTEIN p73-LIKE or p53-RELATED PROTEIN p63.
  45. [45]
  46. [46]
  47. [47]
  48. [48]
    Hay-Wells syndrome is caused by heterozygous ... - PubMed - NIH
    We have recently demonstrated that heterozygous mutations in the p63 gene are the major cause of EEC syndrome.
  49. [49]
    EEC syndrome - Orphanet
    In more than 90% of cases, EEC is due to missense mutations in the sequence of the TP63 ... These cases correspond to the classical EEC syndrome (EEC type 3) and ...
  50. [50]
  51. [51]
    p63 and ZNF148 cooperate to regulate head and neck squamous ...
    Jul 7, 2025 · Our findings reveal a p63/ZNF148/cyclin D1 axis driving cancer progression, offering insights into the molecular basis of head and neck tumors.P63 And Znf148 Cooperate To... · Results · P63 And Znf148 Promote The...
  52. [52]
    Co-activation of super-enhancer-driven CCAT1 by TP63 and SOX2 ...
    Sep 6, 2018 · In squamous cancer cells, overexpression of either SOX2 or TP63 promotes proliferation and tumorigenesis, suggesting oncogenic functions of ...
  53. [53]
    Significance of p63 Amplification and Overexpression in Lung ...
    The p63 genomic sequence was amplified in 88% of squamous carcinomas, in 42% of large cell carcinomas, and in 11% of adenocarcinomas of the lung. The ...
  54. [54]
    p63 in Squamous Cell Carcinoma of the Skin: More Than a Stem ...
    The p63 gene is often overexpressed in squamous cell carcinomas; however, how its overexpression contributes to tumor formation and expansion is still ...
  55. [55]
    DNA Methylation and P53 Immunohistochemistry as Prognostic ...
    Methylation of the IRF6 promoter may be a marker of cancer risk in patients with VLS. ... Differential hypermethylation of genes in vulvar cancer and ...
  56. [56]
    p63 is a suppressor of tumorigenesis and metastasis interacting with ...
    Jul 15, 2011 · p63, as an 'epithelial organizer', directly impinges on epidermal mesenchimal transition, stemness, senescence, cell death and cell cycle arrest.P63 And 'la Famiglia' P53 · P63 Expression In Cancer · P63 Is A Suppressor Of...
  57. [57]
    The analysis of the pyroptosis-related genes and hub gene TP63 ...
    Pyroptosis is a type of programmed cell death that is associated with tumor development, prognosis, and therapeutic response.Missing: evasion | Show results with:evasion
  58. [58]
    Reciprocal inhibition between TP63 and STAT1 regulates anti-tumor ...
    Mar 20, 2024 · Super-enhancer-driven long non-coding RNA LINC01503, regulated by TP63, is over-expressed and oncogenic in squamous cell carcinoma.
  59. [59]
    p63 expression in human tumors and normal tissues - PMC - NIH
    Jan 25, 2021 · For example, p63 immunohistochemistry (IHC) is commonly used to mark cell types with critical impact on cancer diagnosis such as basal cells in ...
  60. [60]
    Diagnostic Utility of Immunohistochemical Staining for p63 ... - Nature
    Dec 1, 2002 · We conclude that p63 staining is at least as sensitive and specific for the identification of basal cells in diagnostic prostate specimens as is high molecular ...
  61. [61]
    Diagnostic utility of p63 and α-methyl acyl Co A racemase...
    In our study, we have concluded that p63 has a sensitivity of 90%, specificity of 100% and accuracy of 95% as shown in Table 1. F1-42 Figure 1: (a and b) H and ...Ihc For P63 And Amacr · Evaluation Of Ihc · Expression Of Amacr In The...
  62. [62]
    [PDF] Evaluation of the Diagnostic Value of Immunohistochemistry ...
    Aug 16, 2021 · In the case of P63 and. CK5/6, sensitivity and specificity were 98%, 96%, 98%, and 82%, respectively. Among basal cell biomarkers, 34βE12 had ...<|separator|>
  63. [63]
    The Use of P63 Immunohistochemistry for the Identification of ... - PMC
    Aug 17, 2010 · One of the top differentially expressed genes between adenocarcinomas (ACs) and SCCs is P63. It is a well-known marker of squamous differentiation.
  64. [64]
    p63 expression in human tumors and normal tissues
    Jan 25, 2021 · The frequencies of p63 positivity was highest in squamous cell carcinomas irrespective of their origin (96–100%), thymic tumors (100%), ...
  65. [65]
    Article p40 (ΔNp63) is superior to p63 for the diagnosis of pulmonary ...
    The reactivity for both p63 and p40 was consistently strong and diffuse; the vast majority (95%) of squamous cell carcinomas had 90–100% of tumor cells ...
  66. [66]
    Diagnostic Utility of P63 and CD10 in Distinguishing Cutaneous ...
    P63 was positive in 9/10 SCSCCs (90%), with most demonstrating strong and diffuse staining. One SCSCC was negative for p63, but positive with two cytokeratin ...
  67. [67]
    Evaluation of Contemporary Prostate and Urothelial Lineage ...
    The urothelial markers tested were GATA3, S100P, p63, CK5/6, CK7, and CK20, and the prostate-associated markers were PSA, prostate specific membrane antigen ...
  68. [68]
    Prostate Carcinoma and Its Mimics in Needle Core Biopsies
    Sep 1, 2008 · 11 p63 is comparable to HMCK in sensitivity and specificity in needle biopsies,11 although some studies have suggested that p63 has better ...
  69. [69]
    A Rare Case of TP63-Associated Lymphopenia Revealed by ...
    Oct 9, 2024 · Pathogenic variants in the TP63 gene are linked to a spectrum of syndromes, including Ectrodactyly, Ectodermal Dysplasia, and Cleft Lip ...
  70. [70]
    (PDF) Ectrodactyly, Ectodermal Dysplasia and Cleft Lip/Palate ...
    Jan 6, 2025 · ... Cleft Lip/Palate Syndrome (EEC) in Patients with TP63 Variants. January 2024; Middle East Journal of Medical Genetics 13(1):9-15. DOI:10.21608 ...
  71. [71]
    APR-246/PRIMA-1MET rescues epidermal differentiation in skin ...
    Jan 25, 2013 · We recently showed that APR-246 can restore DNA binding, target gene expression, and proapoptotic activity to mutant isoforms of TAp63γ in human ...
  72. [72]
    PRIMA-1Met/APR-246 Induces Apoptosis and Tumor Growth Delay ...
    These results suggest that PRIMA-1Met induces cancer cell death in DMS153 ... PRIMA-1(MET)/APR-246 targets mutant forms of p53 family members p63 and p73.
  73. [73]
    Eprenetapopt (APR-246) and Azacitidine in TP53-Mutant ...
    Jan 15, 2021 · Here, we report the safety and efficacy findings from the phase Ib/II trial evaluating combined treatment with eprenetapopt and azacitidine in ...
  74. [74]
    p53 biology and reactivation for improved therapy in MDS and AML
    Mar 13, 2024 · Two, phase Ib/II clinical trials with APR-246 have been concluded so far. Both studies were designed to recruit patients with TP53 gene ...
  75. [75]
    Maintaining protein stability of ∆Np63 via USP28 is required by ...
    Mar 4, 2020 · The study reveals that squamous tumours are dependent on the expression of the deubiquitylase USP28. Inhibition of USP28 destabilises ΔNp63 ...Missing: PROTAC | Show results with:PROTAC
  76. [76]
    ΔNp63 in squamous cell carcinoma: defining the oncogenic routes ...
    Initially, it was hypothesized that the oncogenic role of ΔNp63 in SCC mainly relies on its ability to act as a dominant‐negative factor to p53/p73 proteins and ...
  77. [77]
    Allele-specific CRISPR- engineered Cpf1 genome editing to treat ...
    EEC syndrome is a rare multiple congenital anomaly disease characterized by the combination of ectrodactyly ("claw-like hand") and anomalies of the palate ...
  78. [78]
    EEC-Clear: towards customized allele-specific CRISPR/Cas gene ...
    The disease is dominantly inherited and, in over 90% of cases, is caused by mutations in the TP63 gene, encoding for p63. This protein is crucial for both ...Missing: 2024 | Show results with:2024
  79. [79]
    Physical association of HDAC1 and HDAC2 with p63 mediates ... - NIH
    These effects are recapitulated upon targeting the p63/HDAC complex selectively with class I/II HDAC inhibitors using both in vitro and in vivo models.Missing: vulvar | Show results with:vulvar
  80. [80]
    Expression pattern of class I histone deacetylases in vulvar ...
    Oct 26, 2011 · The development of HDAC inhibitors has identified the utility of HDACs as a therapeutic target. Little is known about the epigenetic regulation ...Missing: p63 | Show results with:p63
  81. [81]
    ΔNp63 in squamous cell carcinoma: defining the oncogenic routes ...
    Mar 7, 2019 · Initially, it was hypothesized that the oncogenic role of ΔNp63 in SCC mainly relies on its ability to act as a dominant-negative factor to p53/ ...<|control11|><|separator|>
  82. [82]
  83. [83]
    Distinct p63 and p73 Protein Interactions Predict Specific Functions ...
    We have found that p73 and p63 cooperate in the genome stability surveillance in proliferating cells; p73 specific interactors contribute to the ...Missing: HNRPAB | Show results with:HNRPAB
  84. [84]
    DARPins detect the formation of hetero-tetramers of p63 and p73 in ...
    Oct 12, 2023 · Here we report the generation and characterization of Designed Ankyrin Repeat Proteins (DARPins) that bind with high affinity and selectivity to the p63 2 /p73 ...
  85. [85]
    Structural diversity of p63 and p73 isoforms - PMC - PubMed Central
    The oligomerization domain of p63 and p73 contain an additional helix that is necessary for stabilizing the tetrameric states. During evolution this helix got ...Missing: Kd | Show results with:Kd
  86. [86]
    Epigenetic priming of an epithelial enhancer by p63 and CTCF ... - NIH
    Dec 8, 2023 · We demonstrated a physical interaction between p63 and CTCF in vitro, therefore, it is plausible that p63 co-operates with CTCF to establish ...
  87. [87]
  88. [88]
  89. [89]
  90. [90]
  91. [91]
  92. [92]
  93. [93]
  94. [94]
    A global analysis of the complex landscape of isoforms and ...
    Aug 7, 2015 · The TP63 gene generates full-length transactivating TA isoforms from an upstream promoter whereas an intronic promoter regulates the expression ...
  95. [95]
    TAp63γ is the primary isoform of TP63 for tumor suppression but not ...
    Feb 6, 2025 · TP63 is expressed as TAp63 and ΔNp63 from the P1 and P2 promoters, respectively. While TAp63 and ΔNp63 are expressed as three TAp63α/β/γ and ...<|control11|><|separator|>
  96. [96]
    Epigenetic regulation of p63 blocks squamous-to-neuroendocrine ...
    Oct 9, 2024 · ΔNp63α overexpression resulted in the ectopic protein expression of basal cell markers KRT5, KRT14, and KRT15 (Figs. 5C and 6, E and F, and ...
  97. [97]
    miR-203 represses 'stemness' by repressing ΔNp63 - Nature
    May 16, 2008 · miR-203, by regulating the ΔNp63 expression level, is a key molecule controlling the p63-dependent proliferative potential of epithelial precursor cells.Missing: TP63 | Show results with:TP63
  98. [98]
    TAp63 Is a Transcriptional Target of NF-κB - PMC - PubMed Central
    TAp63 is a transcriptional target of NF-κB, which may play a role in cell proliferation, differentiation and survival upon NF-κB activation by various stimuli.Missing: TP63 | Show results with:TP63
  99. [99]
    TGFβ and EGF signaling orchestrates the AP-1- and p63 ...
    Apr 29, 2020 · The members of the AP-1 family of transcription factors regulate gene expression in response to a large number of stimuli and pathways, ...Missing: TP63 | Show results with:TP63
  100. [100]
    TAp63 determines the fate of oocytes against DNA damage - Science
    Dec 21, 2022 · The deletion of p63 rescued the primordial follicles and evaded the apoptosis pathway in oocytes against DOXO treatment, supporting the previous ...
  101. [101]
    Oocytes mount a noncanonical DNA damage response involving ...
    Mar 30, 2020 · In keeping with bypass of TAp63-mediated apoptosis at milder degrees of injury, most primordial follicles survive the mild oocyte DNA damage ...Introduction · Results · Discussion · Materials and methods
  102. [102]
    Maintaining protein stability of ∆Np63 via USP28 is required by ...
    Apr 7, 2020 · Here, we report that the deubiquitylase USP28 stabilizes ∆Np63 and maintains elevated ∆NP63 levels in SCC by counteracting its proteasome-mediated degradation.
  103. [103]
    The E3 ubiquitin ligase Itch controls the protein stability of p63 - PMC
    To determine whether Itch-dependent ubiquitylation of p63α promotes p63α degradation, we measured steady-state levels of p63 isoforms in the presence or absence ...
  104. [104]
    The protein stability and transcriptional activity of p63alpha are ...
    Here we show that p63alpha, but not p63beta and gamma, is sumoylated in vitro and in vivo at a single lysine residue, K637, in the post-SAM domain.Missing: phosphorylation acetylation review
  105. [105]
    The Protein Stability and Transcriptional Activity of p63α are ...
    Here we show that p63α, but not p63β and γ, is sumoylated in vitro and in vivo at a single lysine residue, K637, in the post-SAM domain. SUMO-1 attachment ...Missing: retention | Show results with:retention