IndraLab
Statements
TP53 is active.
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"P38 regulates p53, but also in p53-defective tumor cells rewire their checkpoint response and become dependent in the p38/mk2 pathway in mcf-7 cells, p38 kinase activated p53 more effectively than other members of the ras pathway. p53 and p38 kinase exist in the same physical complex, and co-expression of p38 stabilized p53 protein. In vitro, p38 kinase phosphorylated p53 at ser33 and ser46, a newly identified site."
"Dyrk1a phosphorylates p53 and inhibits proliferation of embryonic neuronal cells. we found that dyrk1a phosphorylates p53 at ser-15 in vitro and in immortalized rat embryonic hippocampal progenitor h19-7 cells. In addition, dyrk1a-induced p53 phosphorylation at ser-15 led to a robust induction of p53 target genes"
"Protein serine/threonine phosphatase-1 dephosphorylates p53 at Ser-15 and Ser-37 to modulate its transcriptional and apoptotic activities|In addition, our results reveal that one of the molecular mechanisms by which PP-1 promotes cell survival is to dephosphorylate p53, and thus negatively regulate p53-dependent death pathway."
"Protein serine/threonine phosphatase-1 dephosphorylates p53 at Ser-15 and Ser-37 to modulate its transcriptional and apoptotic activities|In addition, our results reveal that one of the molecular mechanisms by which PP-1 promotes cell survival is to dephosphorylate p53, and thus negatively regulate p53-dependent death pathway."
"PPM1D binds Chk1 and dephosphorylates the ATR-targeted phospho-Ser 345, leading to decreased Chk1 kinase activity. PPM1D also dephosphorylates p53 at phospho-Ser 15. PPM1D dephosphorylations are correlated with reduced cellular intra-S and G2/M checkpoint activity in response to DNA damage induced by ultraviolet and ionizing radiation. Thus, a primary function of PPM1D may be to reverse the p53 and Chk1-induced DNA damage and cell cycle checkpoint responses and return the cell to a homeostatic state following completion of DNA repair."
"Here we show that the direct association between a p53 n-terminal peptide and mdm2 is disrupted by phosphorylation of the peptide on thr(18) but not by phosphorylation at other n-terminal sites, including ser(15) and ser(37). Thr(18) was phosphorylated in vitro by casein kinase (ck1)."
"A cell-free ser(20) phosphorylation site assay was used to identify a broad range of calcium calmodulin kinase superfamily members, including chk2, chk1, dapk-1, dapk-3, drak-1, and ampk, as ser(20) kinases.Evaluation of these calcium calmodulin kinase superfamily members as candidate ser(20) kinases in vivo has shown that only chk1 or dapk-1 can stimulate p53 transactivation and induce ser(20) phosphorylation of p53."
"Dual-specificity phosphatase 26 is a novel p53 phosphatase and inhibits p53 tumor suppressor functions in human neuroblastoma|Inhibiting DUSP26 expression in the IMR-32 neuroblastoma cell line enhanced doxorubicin-induced p53 phosphorylation at Ser20 and Ser37, p21, Puma, Bax expression as well as apoptosis"
"The tumour suppressor protein p53 is stabilised and activated in response to ionising radiation. This is known to depend on the kinase atm;recent results suggest atm acts via the downstream kinase chk2/hcds1, which stabilises p53 at least in part by direct phosphorylation of residue serine 20"
"These findings strongly suggest that jnks are the major direct signaling mediators of uvb-induced p53 phosphorylation at serine 20. furthermore, phosphorylation of p53 at serine 20 by uvb-activated jnks and uvb-induced p53-dependent transcriptional activity were suppressed in jnk1 or jnk2 knockout (jnk1(-/-) or jnk2(-/-)) cells."
"These findings strongly suggest that jnks are the major direct signaling mediators of uvb-induced p53 phosphorylation at serine 20. furthermore, phosphorylation of p53 at serine 20 by uvb-activated jnks and uvb-induced p53-dependent transcriptional activity were suppressed in jnk1 or jnk2 knockout (jnk1(-/-) or jnk2(-/-)) cells."
"A cell-free ser(20) phosphorylation site assay was used to identify a broad range of calcium calmodulin kinase superfamily members, including chk2, chk1, dapk-1, dapk-3, drak-1, and ampk, as ser(20) kinases.Evaluation of these calcium calmodulin kinase superfamily members as candidate ser(20) kinases in vivo has shown that only chk1 or dapk-1 can stimulate p53 transactivation and induce ser(20) phosphorylation of p53."
"Although the stabilization of p53 was apparently concordant with its phosphorylation on N-terminal serine residues in HFFF-2 cells, it did not require the phosphorylation of Ser15 or Ser20 by ATM, a cellular kinase known to phosphorylate and promote the stabilization of p53 in response to DNA damage."
"Protein serine/threonine phosphatase-1 dephosphorylates p53 at Ser-15 and Ser-37 to modulate its transcriptional and apoptotic activities|In addition, our results reveal that one of the molecular mechanisms by which PP-1 promotes cell survival is to dephosphorylate p53, and thus negatively regulate p53-dependent death pathway."
"Protein serine/threonine phosphatase-1 dephosphorylates p53 at Ser-15 and Ser-37 to modulate its transcriptional and apoptotic activities|In addition, our results reveal that one of the molecular mechanisms by which PP-1 promotes cell survival is to dephosphorylate p53, and thus negatively regulate p53-dependent death pathway."
"Protein serine/threonine phosphatase-1 dephosphorylates p53 at Ser-15 and Ser-37 to modulate its transcriptional and apoptotic activities|In addition, our results reveal that one of the molecular mechanisms by which PP-1 promotes cell survival is to dephosphorylate p53, and thus negatively regulate p53-dependent death pathway."
"We found that dusp26 promotes the resistance of human neuroblastoma to doxorubicin-induced apoptosis by acting as a p53 phosphatase to downregulate p53 tumor suppressor function in neuroblastoma cells. / we found that dusp26 binds to p53 and dephosphorylates p53 at ser20 and ser37."
"The cell cycle checkpoint kinases CHK1 and CHK2 have been shown to phosphorylate multiple sites in the N-terminal domain of p53, consequently leading to p53 stabilization and activation. Phosphorylation of at least three of these sites, Ser366, Ser378, and Thr387, was induced by DNA damage. On activation, both of these kinases also phosphorylate multiple sites in the p53 N-terminal domain. These include Ser15, Thr18, Ser20, and Ser37, which are all DNA-damageinducible sites"
"Dual-specificity phosphatase 26 is a novel p53 phosphatase and inhibits p53 tumor suppressor functions in human neuroblastoma|Inhibiting DUSP26 expression in the IMR-32 neuroblastoma cell line enhanced doxorubicin-induced p53 phosphorylation at Ser20 and Ser37, p21, Puma, Bax expression as well as apoptosis"
"the present study it is shown that in apoptotic PC12 cells the levels of p53 and Cdk5 increase concomitantly. Further, Cdk5/p25 effectively phosphorylates recombinant p53 in vitro. Transient transfection of Cdk5/p25 into cells results in an increase in p53 levels, as well as the expression of the p53-responsive genes p21 and Bax. Furthermore, evidence is provided that increased Cdk5 activity increases p53 transcriptional activity significantly, suggesting that p53 is modulated in situ by Cdk5."
"The human Cdc14 phosphatases interact with and dephosphorylate the tumor suppressor protein p53|. Furthermore, the hCdc14 phosphatases were found to dephosphorylate p53 specifically at the p34Cdc2/clb phosphorylation site (p53-phosphor-Ser315)|Earlier studies showed that Ser315 phosphorylation increases the sequence-specific DNA binding capacity of p53, suggesting that Ser315 phosphorylation is an activating modification"
"The human Cdc14 phosphatases interact with and dephosphorylate the tumor suppressor protein p53|. Furthermore, the hCdc14 phosphatases were found to dephosphorylate p53 specifically at the p34Cdc2/clb phosphorylation site (p53-phosphor-Ser315)|Earlier studies showed that Ser315 phosphorylation increases the sequence-specific DNA binding capacity of p53, suggesting that Ser315 phosphorylation is an activating modification"
"In mcf-7 cells, p38 kinase activated p53 more effectively than other members of the ras pathway. p53 and p38 kinase exist in the same physical complex, and co-expression of p38 stabilized p53 protein. In vitro, p38 kinase phosphorylated p53 at ser33 and ser46, a newly identified site."
"P38 regulates p53, but also in p53-defective tumor cells rewire their checkpoint response and become dependent in the p38/mk2 pathway in mcf-7 cells, p38 kinase activated p53 more effectively than other members of the ras pathway. p53 and p38 kinase exist in the same physical complex, and co-expression of p38 stabilized p53 protein. In vitro, p38 kinase phosphorylated p53 at ser33 and ser46, a newly identified site."
"P38 regulates p53, but also in p53-defective tumor cells rewire their checkpoint response and become dependent in the p38/mk2 pathway in mcf-7 cells, p38 kinase activated p53 more effectively than other members of the ras pathway. p53 and p38 kinase exist in the same physical complex, and co-expression of p38 stabilized p53 protein. In vitro, p38 kinase phosphorylated p53 at ser33 and ser46, a newly identified site."
"In response to ionizing radiation (ir), atm, the gene product mutated in ataxia telangiectasia, stabilizes and activates p53 through phosphorylation of ser15 and (indirectly) ser20. Here we show that phosphorylation of p53 on ser46, a residue important for p53 apoptotic activity, as well as on ser9, in response to ir also is dependent on the atm protein kinase. one pathway involves the phosphorylation of p53 and its negative regulator mdm2 by ataxia telangiectasia mutated (atm) and chk2 causing p53 activation and stabilization."
"We show here that moz is an acetyltransferase of p53 at k120 and k382 and colocalizes with p53 in promyelocytic leukemia (pml) nuclear bodies following cellular stress. The moz-pml-p53 interaction enhances moz-mediated acetylation of p53, and this ternary complex enhances p53-dependent p21 expression"
"We show here that moz is an acetyltransferase of p53 at k120 and k382 and colocalizes with p53 in promyelocytic leukemia (pml) nuclear bodies following cellular stress. The moz-pml-p53 interaction enhances moz-mediated acetylation of p53, and this ternary complex enhances p53-dependent p21 expression"
"P38 regulates p53, but also in p53-defective tumor cells rewire their checkpoint response and become dependent in the p38/mk2 pathway in mcf-7 cells, p38 kinase activated p53 more effectively than other members of the ras pathway. p53 and p38 kinase exist in the same physical complex, and co-expression of p38 stabilized p53 protein. In vitro, p38 kinase phosphorylated p53 at ser33 and ser46, a newly identified site."
"P38 regulates p53, but also in p53-defective tumor cells rewire their checkpoint response and become dependent in the p38/mk2 pathway in mcf-7 cells, p38 kinase activated p53 more effectively than other members of the ras pathway. p53 and p38 kinase exist in the same physical complex, and co-expression of p38 stabilized p53 protein. In vitro, p38 kinase phosphorylated p53 at ser33 and ser46, a newly identified site."
"In mcf-7 cells, p38 kinase activated p53 more effectively than other members of the ras pathway. p53 and p38 kinase exist in the same physical complex, and co-expression of p38 stabilized p53 protein. In vitro, p38 kinase phosphorylated p53 at ser33 and ser46, a newly identified site."
"P38 regulates p53, but also in p53-defective tumor cells rewire their checkpoint response and become dependent in the p38/mk2 pathway in mcf-7 cells, p38 kinase activated p53 more effectively than other members of the ras pathway. p53 and p38 kinase exist in the same physical complex, and co-expression of p38 stabilized p53 protein. In vitro, p38 kinase phosphorylated p53 at ser33 and ser46, a newly identified site."
"P38 regulates p53, but also in p53-defective tumor cells rewire their checkpoint response and become dependent in the p38/mk2 pathway in mcf-7 cells, p38 kinase activated p53 more effectively than other members of the ras pathway. p53 and p38 kinase exist in the same physical complex, and co-expression of p38 stabilized p53 protein. In vitro, p38 kinase phosphorylated p53 at ser33 and ser46, a newly identified site."
"Atm/atr are generally sensors of dna damage, but, together with the checkpoint kinases chk1 and chk2, they also function as response effectors by phosphorylation of key substrates, such as p53, brca1, and nbs1. In particular, p53 phosphorylation leads to protein accumulation and activation, which in turn promotes cell-cycle arrest or apoptosis."
"The cell cycle checkpoint kinases CHK1 and CHK2 have been shown to phosphorylate multiple sites in the N-terminal domain of p53, consequently leading to p53 stabilization and activation. Phosphorylation of at least three of these sites, Ser366, Ser378, and Thr387, was induced by DNA damage."
"The cell cycle checkpoint kinases CHK1 and CHK2 have been shown to phosphorylate multiple sites in the N-terminal domain of p53, consequently leading to p53 stabilization and activation. Phosphorylation of at least three of these sites, Ser366, Ser378, and Thr387, was induced by DNA damage."
"Jnk phosphorylated p53 at t81 in response to dna damage and stress-inducing agents, as determined by phospho-specific antibodies to t81 . Jun NH2-terminal kinase phosphorylation of p53 on Thr-81 is important for p53 stabilization and transcriptional activities in response to stress."
"HDAC8 mediates CM-induced deacetylation of p53.Collectively, these results indicate that although binding to p53 and HDAC8 occurs through distinct regions of the CM protein, simultaneous interaction with HDAC8 and p53 is required for aberrant deacetylation and inactivation of p53."
"We show here that moz is an acetyltransferase of p53 at k120 and k382 and colocalizes with p53 in promyelocytic leukemia (pml) nuclear bodies following cellular stress. The moz-pml-p53 interaction enhances moz-mediated acetylation of p53, and this ternary complex enhances p53-dependent p21 expression"
"We show here that moz is an acetyltransferase of p53 at k120 and k382 and colocalizes with p53 in promyelocytic leukemia (pml) nuclear bodies following cellular stress. The moz-pml-p53 interaction enhances moz-mediated acetylation of p53, and this ternary complex enhances p53-dependent p21 expression"
"Using genetic and biochemical approaches, we show that several subunits of the human SWI/SNF complex bind to the tumor suppressor protein p53 in vivo and in vitro.Molecular connection between p53 and the SWI/SNF complex implicates that (i) the SWI/SNF complex is necessary for p53-driven transcriptional activation, and (ii) the SWI/SNF complex plays an important role in p53-mediated cell cycle control."
"Numb can actually interact in vivo with endogenous mdm2 and p53, resulting in a trimeric complex between the three proteins [10]. This interaction appears to regulate the stability of p53, as reduction of numb levels by rna interference (rnai) causes a decrease in the half-life of p53 and consequently a reduction in steady-state levels of the protein. Consistent with this observation, overexpression of numb increases the level of p53 in both unstressed and stressed cells."
"Unexpectedly, however, emerging evidence implicate maml proteins as exciting key transcriptional co-activators in other signal transduction pathways including: muscle differentiation and myopathies (mef2c), tumor suppressor pathway (p53) and colon carcinoma survival (beta-catenin)."
"Plk1-mediated phosphorylation of topors regulates p53 stability. Herein, we have identified topoisomerase i-binding protein (topors), a p53-binding protein, as a plk1 target. We show that plk1 phosphorylates topors on ser(718) in vivo. Significantly, expression of a plk1-unphosphorylatable topors mutant (s718a) leads to a dramatic accumulation of p53 through inhibition of p53 degradation. Topors is an ubiquitin and small ubiquitin-like modifier ubiquitin-protein isopeptide ligase (sumo e3) ligase. Plk1-mediated phosphorylation of topors inhibits topors-mediated sumoylation of p53, whereas p53 ubiquitination is enhanced, leading to p53 degradation."
"In response to ionizing radiation (ir), atm, the gene product mutated in ataxia telangiectasia, stabilizes and activates p53 through phosphorylation of ser15 and (indirectly) ser20. Here we show that phosphorylation of p53 on ser46, a residue important for p53 apoptotic activity, as well as on ser9, in response to ir also is dependent on the atm protein kinase. one pathway involves the phosphorylation of p53 and its negative regulator mdm2 by ataxia telangiectasia mutated (atm) and chk2 causing p53 activation and stabilization."
TP53 is transcriptionally inactive.
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"We present evidence that ellipticine can restore the transactivation function of several transfected p53 mutants (175 H, 248W, 249S, 273 H, 281G), resulting in the induction of p53-responsive genes (p21(WAF1),MDM2) and activation of a p53-responsive luciferase reporter. Ellipticine also activates mutant p53 function in tumor cells expressing endogenous 194F, 233L, 241F, and 273C mutants. "
"We present evidence that ellipticine can restore the transactivation function of several transfected p53 mutants (175 H, 248W, 249S, 273 H, 281G), resulting in the induction of p53-responsive genes (p21(WAF1),MDM2) and activation of a p53-responsive luciferase reporter. Ellipticine also activates mutant p53 function in tumor cells expressing endogenous 194F, 233L, 241F, and 273C mutants. "
"In these experiments p53â??223Leu was as active as wild-type p53 in transactivation of the reporter construct, whereas p53â??274Phe had no detectable activity (Fig. 4b). Coexpression of p53â??274Phe inhibited transactivation by p53â??223Leu, thus correlating with the above-described effects of this mutant on growth-inhibitory activity of p53â??223Leu. The lack of detectable transactivation activity of p53â??274Phe suggests that the toxicity of this protein to 10(1) cells is mediated not through p21."
"We present evidence that ellipticine can restore the transactivation function of several transfected p53 mutants (175 H, 248W, 249S, 273 H, 281G), resulting in the induction of p53-responsive genes (p21(WAF1),MDM2) and activation of a p53-responsive luciferase reporter. Ellipticine also activates mutant p53 function in tumor cells expressing endogenous 194F, 233L, 241F, and 273C mutants. "
"We present evidence that ellipticine can restore the transactivation function of several transfected p53 mutants (175 H, 248W, 249S, 273 H, 281G), resulting in the induction of p53-responsive genes (p21(WAF1),MDM2) and activation of a p53-responsive luciferase reporter. Ellipticine also activates mutant p53 function in tumor cells expressing endogenous 194F, 233L, 241F, and 273C mutants. "
"We present evidence that ellipticine can restore the transactivation function of several transfected p53 mutants (175 H, 248W, 249S, 273 H, 281G), resulting in the induction of p53-responsive genes (p21(WAF1),MDM2) and activation of a p53-responsive luciferase reporter. Ellipticine also activates mutant p53 function in tumor cells expressing endogenous 194F, 233L, 241F, and 273C mutants. "
"We present evidence that ellipticine can restore the transactivation function of several transfected p53 mutants (175 H, 248W, 249S, 273 H, 281G), resulting in the induction of p53-responsive genes (p21(WAF1),MDM2) and activation of a p53-responsive luciferase reporter. Ellipticine also activates mutant p53 function in tumor cells expressing endogenous 194F, 233L, 241F, and 273C mutants. "
"We present evidence that ellipticine can restore the transactivation function of several transfected p53 mutants (175 H, 248W, 249S, 273 H, 281G), resulting in the induction of p53-responsive genes (p21(WAF1),MDM2) and activation of a p53-responsive luciferase reporter. Ellipticine also activates mutant p53 function in tumor cells expressing endogenous 194F, 233L, 241F, and 273C mutants. "
"Here we show that p53 is phosphorylated by the mitotic kinase Aurora-A at serine 215. Unlike most identified phosphorylation sites of p53 that positively associate with p53 function (Brooks, C. L., and Gu, W. (2003) Curr. Opin. Cell Biol. 15, 164-171), the phosphorylation of p53 by Aurora-A at Ser-215 abrogates p53 DNA binding and transactivation activity."
TP53 is transcriptionally active.
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"In addition, treatment of cells with the PKC activator phorbol ester stimulated the ubiquitination of p53 and reduced its ability to accumulate after stress. H7 did not induce the phosphorylation of human p53 on Ser-15 (Ser-18 in mouse protein), a modification that occurs in response to DNA damage and leads to the release of MDM2 and to transactivation by p53"
"In addition, treatment of cells with the PKC activator phorbol ester stimulated the ubiquitination of p53 and reduced its ability to accumulate after stress. H7 did not induce the phosphorylation of human p53 on Ser-15 (Ser-18 in mouse protein), a modification that occurs in response to DNA damage and leads to the release of MDM2 and to transactivation by p53"
"Fractionation of HeLa nuclear extracts and biochemical analyses indicate that this kinase is distinct from the DNA-dependent protein kinase (DNA-PK) and corresponds to the human cell cycle checkpoint protein ATR. Immunoprecipitation studies of recombinant ATR reveal that catalytic activity of this polypeptide is required for DNA-stimulated phosphorylation of p53 on serine-15. These data suggest that ATR may function upstream of p53 in a signal transduction cascade initiated upon DNA damage and provide a biochemical assay system for ATR activity."
"Fractionation of HeLa nuclear extracts and biochemical analyses indicate that this kinase is distinct from the DNA-dependent protein kinase (DNA-PK) and corresponds to the human cell cycle checkpoint protein ATR. Immunoprecipitation studies of recombinant ATR reveal that catalytic activity of this polypeptide is required for DNA-stimulated phosphorylation of p53 on serine-15. These data suggest that ATR may function upstream of p53 in a signal transduction cascade initiated upon DNA damage and provide a biochemical assay system for ATR activity."
"In the present study, we demonstrate that PP-1 can dephosphorylate p53 at Ser-15 and Ser-37 through co-immunoprecipitation, in vitro and in vivo dephosphorylation assays, overexpression and silence of the gene encoding the catalytic subunit for PP-1. We further show that mutations mimicking constitutive dephosphorylation or phosphorylation of p53 at these sites attenuate or enhance its transcriptional activity, respectively. "
"Co-exposure to C75 and Taxol induced a remarkable nuclear accumulation of activated p38 mitogen-activated protein kinase (p38 MAPK), which was accompanied by a synergistic nuclear accumulation of the p53 tumor-suppressor protein that was phosphorylated at Ser46, a p38 MAPK-regulated pro-apoptotic modification of p53"
"Through direct cloning of p53 binding sequences from human genomic DNA, we have isolated a novel gene, designated p53AIP1 (p53-regulated Apoptosis-Inducing Protein 1), whose expression is inducible by wild-type p53. Ectopically expressed p53AIP1, which is localized within mitochondria, leads to apoptotic cell death through dissipation of mitochondrial A(psi)m. We have found that upon severe DNA damage, Ser-46 on p53 is phosphorylated and apoptosis is induced. In addition, substitution of Ser-46 inhibits the ability of p53 to induce apoptosis and selectively blocks expression of p53AIP1. Our results suggest that p53AIP1 is likely to play an important role in mediating p53-dependent apoptosis, and phosphorylation of Ser-46 regulates the transcriptional activation of this apoptosis-inducing gene."
"Thr18 residue phosphorylation, in the transactivation domain of p53, has been implicated in both disruption of p53-Mdm2 interaction and p300 coactivator recruitment, which acetylates the p53 carboxy terminus. This leads to a decrease in p53 degradation and its subsequent stabilization and to an increase in p53-dependent transactivation activity."
"Thr18 residue phosphorylation, in the transactivation domain of p53, has been implicated in both disruption of p53-Mdm2 interaction and p300 coactivator recruitment, which acetylates the p53 carboxy terminus. This leads to a decrease in p53 degradation and its subsequent stabilization and to an increase in p53-dependent transactivation activity. "
"In the p53-dependent pathway, p53 accumulates following E2F1 expression [29] through activation of the cyclin-dependent kinase inhibitor 2A (CDKN2A) transcript p14ARF, which in turn interacts with mouse double minutes (MDM2), thereby preventing MDM2 from targeting p53 for ubiquitination and subsequent degradation"
"Furthermore, evidence is provided that increased Cdk5 activity increases p53 transcriptional activity significantly, suggesting that p53 is modulated in situ by Cdk5. This is the first demonstration that p53 is a substrate of Cdk5, and that Cdk5 can modulate p53 levels and activity."
"In the p53-dependent pathway, p53 accumulates following E2F1 expression [29] through activation of the cyclin-dependent kinase inhibitor 2A (CDKN2A) transcript p14ARF, which in turn interacts with mouse double minutes (MDM2), thereby preventing MDM2 from targeting p53 for ubiquitination and subsequent degradation"
"Co-exposure to C75 and Taxol induced a remarkable nuclear accumulation of activated p38 mitogen-activated protein kinase (p38 MAPK), which was accompanied by a synergistic nuclear accumulation of the p53 tumor-suppressor protein that was phosphorylated at Ser46, a p38 MAPK-regulated pro-apoptotic modification of p53"
"Pretreatment with an inhibitor of poly(ADP-ribose) polymerase 1 (PARP1), NU1025, nearly doubled the DNA damage produced by 5 microM 3MI, implying that PARP1, which among other activities, functions to repair single-strand breaks in DNA, repaired at least some of the 3MI-induced DNA fragmentation. A key cellular response to DNA damage, phosphorylation, and nuclear localization of p53 was seen at subtoxic levels of 3MI exposure ... from Fig 6, TP53 P@S20"
"In the present study, we demonstrate that PP-1 can dephosphorylate p53 at Ser-15 and Ser-37 through co-immunoprecipitation, in vitro and in vivo dephosphorylation assays, overexpression and silence of the gene encoding the catalytic subunit for PP-1. We further show that mutations mimicking constitutive dephosphorylation or phosphorylation of p53 at these sites attenuate or enhance its transcriptional activity, respectively."
"Here we describe a role for PRAK in tumor suppression by demonstrating that PRAK mediates senescence upon activation by p38 in response to oncogenic ras ... Furthermore, we show that PRAK activates p53 by direct phosphorylation. We propose that phosphorylation of p53 by PRAK following activation of p38 MAPK by ras plays an important role in ras-induced senescence and tumor suppression ... from full text, oncogenic ras is HRAS G12V and TP53 is phosphorylated at S37 ... human primary BJ fibroblasts"
TP53 is inactive.
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"Many posttranslational modifications of p53, such as phosphorylation, dephosphorylation, acetylation and ribosylation, have been shown to occur following cellular stress. Some of these modifications may activate the p53 protein, interfere with MDM2 binding and/or dictate cellular localization of p53."
"Plk1-mediated phosphorylation of topors regulates p53 stabilityherein, we have identified topoisomerase i-binding protein (topors), a p53-binding protein, as a plk1 target. We show that plk1 phosphorylates topors on ser(718) in vivo. Significantly, expression of a plk1-unphosphorylatable topors mutant (s718a) leads to a dramatic accumulation of p53 through inhibition of p53 degradation. Topors is an ubiquitin and small ubiquitin-like modifier ubiquitin-protein isopeptide ligase (sumo e3) ligase. Plk1-mediated phosphorylation of topors inhibits topors-mediated sumoylation of p53, whereas p53 ubiquitination is enhanced, leading to p53 degradation."
"A specific PP2A regulatory subunit, B56gamma, mediates DNA damage-induced dephosphorylation of p53 at Thr55| In this study, we reported that the specific B regulatory subunits of PP2A B56gamma1 and B56gamma3 mediate dephosphorylation of p53 at Thr55. Ablation of the B56gamma protein by RNAi, which abolishes the Thr55 dephosphorylation in response to DNA damage, reduces p53 stabilization, Bax expression and cell apoptosis"
"A specific PP2A regulatory subunit, B56gamma, mediates DNA damage-induced dephosphorylation of p53 at Thr55| In this study, we reported that the specific B regulatory subunits of PP2A B56gamma1 and B56gamma3 mediate dephosphorylation of p53 at Thr55. Ablation of the B56gamma protein by RNAi, which abolishes the Thr55 dephosphorylation in response to DNA damage, reduces p53 stabilization, Bax expression and cell apoptosis"
"Here we show that p53 is phosphorylated by the mitotic kinase aurora-a at serine 215. Unlike most identified phosphorylation sites of p53 that positively associate with p53 function (brooks, c. L., and gu, w. (2003) curr. Opin. Cell biol. 15, 164-171), the phosphorylation of p53 by aurora-a at ser-215 abrogates p53 dna binding and transactivation activity."
"We show that aurora b phosphorylates p53 at s183, t211, and s215 to accelerate the degradation of p53 through the polyubiquitination-proteasome pathway, thus functionally suppressing the expression of p53 target genes involved in cell cycle inhibition and apoptosis (e.g., p21 and puma)."
"We show that aurora b phosphorylates p53 at s183, t211, and s215 to accelerate the degradation of p53 through the polyubiquitination-proteasome pathway, thus functionally suppressing the expression of p53 target genes involved in cell cycle inhibition and apoptosis (e.g., p21 and puma)."
"We show that aurora b phosphorylates p53 at s183, t211, and s215 to accelerate the degradation of p53 through the polyubiquitination-proteasome pathway, thus functionally suppressing the expression of p53 target genes involved in cell cycle inhibition and apoptosis (e.g., p21 and puma)."