| 1999 |
MDM2 binds p73 both in vivo and in vitro but, unlike with p53, does not promote p73 degradation. Instead, MDM2 suppresses p73 transcriptional activity by disrupting the p73-p300/CBP interaction, competing with p73 for binding to the p300/CBP N-terminus. p73 transcriptionally activates MDM2, forming a regulatory loop distinct from the p53-MDM2 loop. |
Co-immunoprecipitation (in vivo and in vitro), transient transfection/CAT reporter assays, apoptosis assays in p53-null cells |
Molecular and cellular biology |
High |
10207051
|
| 1999 |
MDM2 and MDMX bind p73α and p73β and, in contrast to their effect on p53, stabilize p73 protein (increase half-life) and enhance p73-mediated growth suppression and p21 induction. |
Co-immunoprecipitation, half-life assays, growth suppression assays |
Current biology : CB |
Medium |
10469568
|
| 2000 |
Tumor-derived p53 mutants (p53His175 and p53Gly281) physically associate with p73α, β, γ, and δ isoforms in vitro and in vivo. The core domain of mutant p53 is sufficient for the association; both the DNA-binding and oligomerization domains of p73 are required. This interaction functionally inhibits p73 transcriptional activity. |
Co-immunoprecipitation in breast cancer cell lines, in vitro binding, transactivation reporter assays, domain-mapping mutagenesis |
The Journal of biological chemistry |
High |
10884390
|
| 2000 |
E2F-1, c-Myc, and E1A oncogenes induce and activate endogenous p73α and p73β proteins in p53-deficient tumor cells, leading to p73-dependent transcription (p21, HDM2 induction) and apoptosis. A dominant-negative p73 inhibitor blocks oncogene-induced apoptosis. |
Western blot, reporter assays, apoptosis assays with dominant-negative p73 inhibitor in p53-null cells |
The Journal of biological chemistry |
Medium |
11115495
|
| 2000 |
TCR-activation-induced cell death (TCR-AICD) requires both E2F-1 and p73 in a common pathway. E2F-1-null or p73-null primary T cells fail to undergo TCR-mediated apoptosis; dominant-negative E2F-1 or dominant-negative p73 protects T cells, whereas dominant-negative p53 does not. |
Genetic knockout (E2F-1-null, p73-null primary T cells), dominant-negative protein expression, apoptosis assays |
Nature |
High |
11034214
|
| 2001 |
p73 transcription is directly induced by p53 and by p73 itself (autoregulation) through a p53-binding site in the p73 promoter; mutant p53(R249S) and transcriptionally inactive p73β292 do not induce p73 expression. |
Reporter assays with p73 promoter constructs, site-directed mutagenesis of promoter binding site, RT-PCR |
Oncogene |
Medium |
11314010
|
| 2002 |
Combined loss of p63 and p73 (but not either alone) abolishes p53-dependent apoptosis in response to DNA damage in MEFs expressing E1A and in vivo, demonstrating that p63 and p73 are required co-factors for p53-mediated apoptosis. |
Mouse embryo fibroblasts deficient for combinations of p53 family members, E1A oncogene system, in vivo apoptosis assays |
Nature |
High |
11932750
|
| 2002 |
p73 is selectively expressed in Cajal-Retzius (CR) cells of the developing human cortex; in p73-/- mice, Reelin-expressing CR cells are absent at P2 (though early preplate Reelin from calretinin-positive cells remains), indicating p73 is required for CR cell identity/maintenance and cortical hem-derived neocortical development. |
Immunocytochemistry in human prenatal telencephalon, in situ hybridization in p73-/- mice, comparative analysis of p73-/- vs. wild-type cortex |
The Journal of neuroscience |
Medium |
12077194
|
| 2003 |
p73 is induced by a broad range of chemotherapeutic drugs; blocking p73 function with dominant-negative mutant, siRNA, or homologous recombination causes chemoresistance regardless of p53 status; mutant p53 can inactivate p73 and downregulation of mutant p53 enhances chemosensitivity. |
siRNA knockdown, dominant-negative expression, homologous recombination, chemosensitivity assays |
Cancer cell |
High |
12726865
|
| 2004 |
Checkpoint kinases Chk1 and Chk2 control p73 induction at the mRNA level after DNA damage, acting through E2F1 stabilization. Interference with Chk1/Chk2 reduces p73 accumulation; augmentation increases it. E2F1 directs p73 expression both with and without DNA damage. |
Multiple experimental systems including kinase interference and augmentation, RT-PCR for p73 mRNA, E2F1 reporter assays |
Genes & development |
Medium |
15601819
|
| 2004 |
Wwox physically interacts with p73 via its first WW domain; Src kinase phosphorylates Wwox at Tyr33 and enhances its binding to p73. Wwox expression redistributes nuclear p73 to the cytoplasm, suppressing p73 transcriptional activity; cytoplasmic p73 contributes to Wwox pro-apoptotic activity. |
Co-immunoprecipitation, in vitro binding assays, subcellular fractionation, reporter assays, domain mapping |
Proceedings of the National Academy of Sciences of the United States of America |
Medium |
15070730
|
| 2005 |
Itch, a HECT ubiquitin-protein ligase, selectively binds and ubiquitinates p73 (but not p53), targeting p73 for rapid proteasome-dependent degradation. Upon DNA damage, Itch is downregulated, allowing p73 protein levels to rise. |
Co-immunoprecipitation, ubiquitination assays, proteasome inhibitor experiments, Itch knockdown, Western blot for p73 stability |
The EMBO journal |
High |
15678106
|
| 2005 |
TAp73 induces apoptosis via: (i) direct transactivation of Scotin, causing ER stress; (ii) transactivation of PUMA (strong, lethal) and Bax promoters (weak, insufficient alone); and (iii) potential activation of the CD95 death receptor pathway. TAp73 also transactivates the DeltaNp73 promoter, creating a negative feedback. |
Promoter transactivation reporter assays, apoptosis assays in cell culture |
Biochemical and biophysical research communications |
Medium |
15865927
|
| 2006 |
YAP1 (Yes-associated protein 1) interacts with p73 via the p73 PPPY motif and competes with Itch for the same binding site on p73, thereby preventing Itch-mediated ubiquitination and proteasomal degradation of p73. YAP1 knockdown reduces p73 accumulation and apoptosis after cisplatin treatment. |
Co-immunoprecipitation, competition binding assays, ubiquitination assays, siRNA knockdown, cisplatin treatment |
Cell death and differentiation |
High |
17110958
|
| 2006 |
p73 (or p53) directly transactivates endogenous p53 expression through binding to a defined p53-binding site in the p53 promoter; siRNA silencing of p73 reduces p53 transcription, and disruption of p53 autoregulation impairs cell cycle checkpoints and p53-mediated apoptosis. |
siRNA knockdown, reporter assays with p53 promoter mutants, RT-PCR for endogenous p53 mRNA, inducible interfering RNA |
Cancer research |
Medium |
16849542
|
| 2007 |
SIRT1 physically binds p73 and suppresses p73-dependent transcriptional activity; SIRT1 deacetylates p73 both in vivo and in vitro, partially inhibiting p73-induced apoptosis. |
Co-immunoprecipitation, deacetylation assays in vivo and in vitro, reporter assays, apoptosis assays |
Journal of cellular physiology |
Medium |
16998810
|
| 2007 |
Nutlin-3 disrupts endogenous TAp73α-HDM2 binding in p53-null cells, leading to increased p73 transcriptional activity (Noxa, PUMA, p21 upregulation), prolonged p73 half-life, and enhanced apoptosis; p73 siRNA rescues Nutlin-3-treated cells, confirming p73 dependence. |
Co-immunoprecipitation, siRNA knockdown, RT-PCR for target genes, apoptosis assays, p73 half-life measurement |
Oncogene |
Medium |
17700533
|
| 2007 |
Hck (Src-family kinase) interacts with p73 via its SH3 domain and phosphorylates p73 at Tyr28 (distinct from c-Abl which phosphorylates Tyr99). Hck co-expression stabilizes p73 in the cytoplasm (kinase-dependent) and represses p73 transcriptional activity and p73-mediated apoptosis through SH3-domain-dependent mechanisms. |
Co-immunoprecipitation, in vitro binding, site-directed mutagenesis of phosphorylation sites, subcellular fractionation, reporter assays, RT-PCR, apoptosis assays |
BMC molecular biology |
Medium |
17535448
|
| 2008 |
p73 is cleaved by caspase-3 and caspase-8 during apoptosis induced by DNA-damaging drugs and TRAIL. TAp73 and caspase-cleavage products localize to mitochondria; recombinant p73 directly induces cytochrome c release from isolated mitochondria. A transcription-deficient TAp73 mutant enhances TRAIL-induced apoptosis, demonstrating transcription-independent pro-apoptotic function. |
In vitro caspase cleavage assays, subcellular fractionation, mitochondria isolation with cytochrome c release assay, siRNA knockdown, flow cytometry |
Oncogene |
Medium |
18362891
|
| 2009 |
DNA damage-induced p73 activation and subsequent Noxa expression require NF-κB (p65); in p65-null MEFs, genotoxin treatment cannot induce p73 activity or Noxa mRNA expression, and cytochrome c release is compromised. |
p65-null MEFs, microarray gene profiling, RT-PCR, cytochrome c release assays |
Aging |
Medium |
20195489
|
| 2011 |
p73 selectively activates DNA damage repair in esophageal cells exposed to bile acids in acidic conditions via c-Abl kinase-dependent activation; p73 transcriptionally regulates base excision repair glycosylases SMUG1 and MUTYH. p73 deficiency in mice recapitulating bile acid exposure results in increased DNA damage. |
Human DNA repair PCR array, chromatin immunoprecipitation, reporter assays, c-Abl kinase inhibition, organotypic/traditional cell culture, surgical mouse model |
FASEB journal |
Medium |
21891782
|
| 2012 |
Crystal structures of the p73 DNA-binding domain (DBD) tetramer bound to response elements with different spacer lengths reveal that the compact tetramer interface is determined by half-site spacing; a 2-bp spacer unwinds DNA and reduces the tetramerization interface, while a 4-bp spacer prevents tetramerization. Functionally, p73 is more sensitive to spacer length than p53: a 1-bp spacer reduces p73 transactivation by 90%. |
X-ray crystallography, transactivation reporter assays |
Proceedings of the National Academy of Sciences of the United States of America |
High |
22474346
|
| 2013 |
TAp73 activates serine biosynthesis in cancer cells not by directly regulating serine metabolic enzymes but by transcriptionally controlling glutaminase-2 (GLS2), a key glutaminolysis enzyme. p73-driven GLS2 expression converts glutamine to glutamate, which drives serine biosynthesis and GSH synthesis. TAp73 depletion abolishes cancer cell proliferation under serine/glycine deprivation. |
Metabolic profiling, siRNA knockdown, reporter assays, cell proliferation assays under nutrient deprivation |
Oncogene |
Medium |
24186203
|
| 2013 |
TRIM32 (E3 ubiquitin ligase) is a direct transcriptional target of TAp73 in neural progenitor cells; TRIM32 in turn physically interacts with TAp73 and promotes its ubiquitination and degradation, establishing a negative feedback loop. ΔNp73 represses TRIM32 expression. |
ChIP, reporter assays, Co-immunoprecipitation, ubiquitination assays, Western blot |
Cell death & disease |
Medium |
23828567
|
| 2014 |
AMPK phosphorylates p73 on Ser426 in vitro and in vivo. AMPK activation prolongs p73 half-life, increases nuclear p73, and reduces Itch-mediated ubiquitination of p73. Chronic AMPK activation leads to p73-dependent apoptosis only in p53-expressing cells; p73 is required for p53 stabilization under AMPK activation but not under DNA damage. |
In vitro kinase assay, in vivo phosphorylation assay, half-life measurement, ubiquitination assays, p73 knockdown, co-immunoprecipitation |
Cell death and differentiation |
High |
24874608
|
| 2014 |
MDM2 differentially regulates mutant p53 interactions with p63 and p73: MDM2 inhibits p63 binding to p53R175H (conformational mutant) but enhances the weaker p53R273H/p73 interaction. MDM2 can relieve p63 inhibition by p53R175H but forms a trimeric complex with p73 and p53R273H/R175H to enhance p73 inhibition. |
Co-immunoprecipitation, reporter assays, domain mapping |
Oncogene |
Medium |
25417702
|
| 2015 |
NAMPT inhibition stabilizes p73 independently of p53 through increased acetylation and decreased ubiquitination, leading to enhanced autophagy and cancer cell death; these effects are reversed by NMN (the NAMPT enzymatic product), establishing a NAMPT-p73 nexus in cancer cell viability. |
NAMPT pharmacological inhibition and siRNA knockdown, p73 overexpression/knockdown, ubiquitination assays, Western blot, cell viability assays |
Cell death and differentiation |
Medium |
26586573
|
| 2015 |
p73 is required for ependymal cell maturation and planar cell polarity establishment in the developing SVZ; p73-deficient ependymal cells have impaired ciliogenesis and fail to organize into pinwheels, disrupting SVZ niche architecture and neurogenesis. |
Genetic knockout mouse model (p73-null), immunofluorescence, electron microscopy, neurogenesis assays |
Developmental neurobiology |
Medium |
26482843
|
| 2016 |
p73 is expressed in multiciliated cells (MCCs) and is required for MCC differentiation; p73 directly regulates Foxj1 (a master transcriptional regulator of multiciliogenesis) and >100 cilia-associated target genes. Loss of p73 causes defects in ciliogenesis explaining hydrocephalus, hippocampal dysgenesis, sterility, and chronic inflammation in p73-null mice. |
ChIP-seq (p73 and p63) in murine tracheal cells, genetic knockout mice, reporter assays, immunofluorescence |
Cell reports |
High |
26947080
|
| 2016 |
TAp73 directly activates POSTN (periostin) transcription in glioblastoma cells, conferring an invasive phenotype. POSTN overexpression rescues the reduced invasiveness caused by p73 knockdown, placing POSTN downstream of TAp73 in a pro-invasion pathway. |
ChIP, reporter assays, siRNA knockdown, invasion assays, rescue experiments with POSTN overexpression |
Oncotarget |
Medium |
26930720
|
| 2018 |
Δ133p53 forms a complex with p73 upon γ-irradiation; co-expression of Δ133p53 and p73 synergistically promotes DNA DSB repair (HR, NHEJ, SSA) by jointly binding to both a Δ133p53-responsive element and a p73-RE in the promoters of RAD51, LIG4, and RAD52. Loss of p73 increases DNA damage accumulation and leads to cell cycle arrest and senescence. |
Co-immunoprecipitation, ChIP, reporter assays, γ-irradiation, HR/NHEJ/SSA repair assays, siRNA knockdown |
Cell death and differentiation |
Medium |
29511339
|
| 2018 |
JNK-mediated phosphorylation of Thr81 in the proline-rich domain of p53 enables wild-type p53 (as well as mutant p53) to form a complex with p73. Wild-type p53/p73 dimerization facilitates expression of apoptotic target genes (PUMA, BAX) and promotes apoptosis; mutant p53/p73 complex suppresses apoptosis. |
Co-immunoprecipitation, phosphorylation assays, structural modeling, reporter assays, apoptosis assays, site-directed mutagenesis of Thr81 |
Science signaling |
Medium |
29615516
|
| 2018 |
TAp73 is an essential regulator of ependymal planar cell polarity (PCP) by modulating actin and microtubule cytoskeleton dynamics. TAp73 regulates translational PCP and actin dynamics through modulation of non-muscle myosin-II activity and controls asymmetric localization of PCP-core signaling modules and polarized microtubule dynamics for rotational PCP. |
TAp73-specific knockout mice, immunofluorescence for PCP proteins and cytoskeletal markers, analysis of myosin-II activity |
Cell death & disease |
Medium |
30518789
|