scholarly journals Activation of the DNA-binding ability of latent p53 protein by protein kinase C is abolished by protein kinase CK2

2004 ◽  
Vol 378 (3) ◽  
pp. 939-947 ◽  
Author(s):  
Šárka POSPÍŠILOVÁ ◽  
Václav BRÁZDA ◽  
Kateřina KUCHAŘÍKOVÁ ◽  
M. Gloria LUCIANI ◽  
Ted R. HUPP ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Protein Kinase ◽  
Dna Binding ◽  
Protein Kinase Ck2 ◽  
P53 Protein ◽  
Cyclin A ◽  
Binding Activity ◽  
Dna Binding Activity ◽  
Kinase C ◽  
Kinase Ck2

p53 is one of the most important regulators of cell proliferation and differentiation and of programmed cell death, triggering growth arrest and/or apoptosis in response to different cellular stress signals. The sequence-specific DNA-binding function of p53 protein can be activated by several different stimuli that modulate the C-terminal domain of this protein. The predominant mechanism of activation of p53 sequence-specific DNA binding is phosphorylation at specific sites. For example, phosphorylation of p53 by PKC (protein kinase C) occurs in undamaged cells, resulting in masking of the epitope recognized by monoclonal antibody PAb421, and presumably promotes steady-state levels of p53 activity in cycling cells. In contrast, phosphorylation by cdk2 (cyclin-dependent kinase 2)/cyclin A and by the protein kinase CK2 are both enhanced in DNA-damaged cells. We determined whether one mechanism to account for this mutually exclusive phosphorylation may be that each phosphorylation event prevents modification by the other kinase. We used non-radioactive electrophoretic mobility shift assays to show that C-terminal phosphorylation of p53 protein by cdk2/cyclin A on Ser315 or by PKC on Ser378 can efficiently stimulate p53 binding to DNA in vitro, as well as binding of the monoclonal antibody Bp53-10, which recognizes residues 371–380 in the C-terminus of p53. Phosphorylation of p53 by CK2 on Ser392 induces its DNA-binding activity to a much lower extent than phosphorylation by cdk2/cyclin A or PKC. In addition, phosphorylation by CK2 strongly inhibits PKC-induced activation of p53 DNA binding, while the activation of p53 by cdk2/cyclin A is not affected by CK2. The presence of CK2-mediated phosphorylation promotes PKC binding to its docking site within the p53 oligomerization domain, but decreases phosphorylation by PKC, suggesting that competition between CK2 and PKC does not rely on the inhibition of PKC–p53 complex formation. These results indicate the crucial role of p53 C-terminal phosphorylation in the regulation of its DNA-binding activity, but also suggest that antagonistic relationships exist between different stress signalling pathways.

A cyclin A-protein kinase complex possesses sequence-specific DNA binding activity: p33cdk2 is a component of the E2F-cyclin A complex

Cell ◽  
1992 ◽  
Vol 68 (1) ◽  
pp. 167-176 ◽  
Author(s):  
Stephen H. Devoto ◽  
Maria Mudryj ◽  
Jonathon Pines ◽  
Tony Hunter ◽  
Joseph R. Nevins
Keyword(s):  
Protein Kinase ◽  
Dna Binding ◽  
Cyclin A ◽  
Binding Activity ◽  
Dna Binding Activity

Activation of protein kinase C decreases phosphorylation of c-Jun at sites that negatively regulate its DNA-binding activity

Cell ◽  
1991 ◽  
Vol 64 (3) ◽  
pp. 573-584 ◽  
Author(s):  
William J. Boyle ◽  
Tod Smeal ◽  
Libert H.K. Defize ◽  
Peter Angel ◽  
James R. Woodgett ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Dna Binding ◽  
Binding Activity ◽  
Dna Binding Activity ◽  
Kinase C

scholarly journals Cross-coupling of signal transduction pathways: the dioxin receptor mediates induction of cytochrome P-450IA1 expression via a protein kinase C-dependent mechanism.

1993 ◽  
Vol 13 (1) ◽  
pp. 677-689 ◽  
Author(s):  
A Berghard ◽  
K Gradin ◽  
I Pongratz ◽  
M Whitelaw ◽  
L Poellinger
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Dna Binding ◽  
Binding Activity ◽  
Dna Binding Activity ◽  
Kinase C ◽  
The Individual ◽  
Dioxin Receptor

Signal transduction by dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin) is mediated by the intracellular dioxin receptor which, in its dioxin-activated state, regulates transcription of target genes encoding drug-metabolizing enzymes, such as cytochrome P-450IA1 and glutathione S-transferase Ya. Exposure of the dioxin receptor to dioxin leads to an apparent translocation of the receptor to the nucleus in vivo and to a rapid conversion of the receptor from a latent, non-DNA-binding form to a species that binds to dioxin-responsive positive control elements in vitro. This DNA-binding form of receptor appears to be a heterodimeric complex with the helix-loop-helix factor Arnt. In this study, we show that activation of the cytochrome P-450IA1 gene and minimal dioxin-responsive reporter constructs by the dioxin receptor was inhibited following prolonged treatment of human keratinocytes with the phorbol ester 12-O-tetradecanoylphorbol-13-acetate. Inhibition of the receptor-mediated activation response was also achieved by treatment of the cells with a number of protein kinase inhibitors, one of which, calphostin C, shows selectivity for protein kinase C. Taken together, these data suggest that protein kinase C-dependent phosphorylation may play an essential role in the dioxin signaling pathway. This hypothesis is supported by the observation that pretreatment of the cells with 12-O-tetradecanoylphorbol-13-acetate inhibited the DNA-binding activity of the dioxin receptor in vivo. In vivo, the dioxin receptor was found to be a phosphoprotein. In vitro, dephosphorylation of the ligand-activated, heteromeric dioxin receptor form or dephosphorylation of the individual ligand-binding and Arnt receptor subunits inhibited the xenobiotic response element-binding activity. Moreover, dephosphorylation experiments with the individual receptor subunits prior to assembly of the xenobiotic response element-binding receptor form indicated that phosphorylation seemed to be important for the DNA-binding activity per se of the receptor, whereas Arnt appeared to require phosphorylation to interact with the receptor. Finally, a protein kinase C inhibitor-sensitive cytosolic catalytic activity that could restore the DNA-binding activity of the dephosphorylated dioxin receptor form was identified.

scholarly journals Aggregation of the FcRI in Mast Cells Induces the Synthesis of Fos-interacting Protein and Increases Its DNA Binding Activity: The Dependence on Protein Kinase C-

1996 ◽  
Vol 271 (3) ◽  
pp. 1514-1519 ◽  
Author(s):  
Iris Lewin ◽  
Jasmine Jacob-Hirsch ◽  
Zhao Cheng Zang ◽  
Valentina Kupershtein ◽  
Zoltan Szallasi ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Mast Cells ◽  
Protein Kinase ◽  
Dna Binding ◽  
Binding Activity ◽  
Interacting Protein ◽  
Dna Binding Activity ◽  
Kinase C

Cross-coupling of signal transduction pathways: the dioxin receptor mediates induction of cytochrome P-450IA1 expression via a protein kinase C-dependent mechanism

1993 ◽  
Vol 13 (1) ◽  
pp. 677-689
Author(s):  
A Berghard ◽  
K Gradin ◽  
I Pongratz ◽  
M Whitelaw ◽  
L Poellinger
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Dna Binding ◽  
Binding Activity ◽  
Dna Binding Activity ◽  
Kinase C ◽  
The Individual ◽  
Dioxin Receptor

Signal transduction by dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin) is mediated by the intracellular dioxin receptor which, in its dioxin-activated state, regulates transcription of target genes encoding drug-metabolizing enzymes, such as cytochrome P-450IA1 and glutathione S-transferase Ya. Exposure of the dioxin receptor to dioxin leads to an apparent translocation of the receptor to the nucleus in vivo and to a rapid conversion of the receptor from a latent, non-DNA-binding form to a species that binds to dioxin-responsive positive control elements in vitro. This DNA-binding form of receptor appears to be a heterodimeric complex with the helix-loop-helix factor Arnt. In this study, we show that activation of the cytochrome P-450IA1 gene and minimal dioxin-responsive reporter constructs by the dioxin receptor was inhibited following prolonged treatment of human keratinocytes with the phorbol ester 12-O-tetradecanoylphorbol-13-acetate. Inhibition of the receptor-mediated activation response was also achieved by treatment of the cells with a number of protein kinase inhibitors, one of which, calphostin C, shows selectivity for protein kinase C. Taken together, these data suggest that protein kinase C-dependent phosphorylation may play an essential role in the dioxin signaling pathway. This hypothesis is supported by the observation that pretreatment of the cells with 12-O-tetradecanoylphorbol-13-acetate inhibited the DNA-binding activity of the dioxin receptor in vivo. In vivo, the dioxin receptor was found to be a phosphoprotein. In vitro, dephosphorylation of the ligand-activated, heteromeric dioxin receptor form or dephosphorylation of the individual ligand-binding and Arnt receptor subunits inhibited the xenobiotic response element-binding activity. Moreover, dephosphorylation experiments with the individual receptor subunits prior to assembly of the xenobiotic response element-binding receptor form indicated that phosphorylation seemed to be important for the DNA-binding activity per se of the receptor, whereas Arnt appeared to require phosphorylation to interact with the receptor. Finally, a protein kinase C inhibitor-sensitive cytosolic catalytic activity that could restore the DNA-binding activity of the dephosphorylated dioxin receptor form was identified.

scholarly journals Induction of the DNA-binding activity of c-jun/c-fos heterodimers by the hepatitis B virus transactivator pX.

1994 ◽  
Vol 14 (2) ◽  
pp. 989-998 ◽  
Author(s):  
G Natoli ◽  
M L Avantaggiati ◽  
P Chirillo ◽  
A Costanzo ◽  
M Artini ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Hepatitis B Virus ◽  
Protein Kinase ◽  
Dna Binding ◽  
Hepatitis B ◽  
Cell Lines ◽  
Binding Activity ◽  
Dna Binding Activity ◽  
Kinase C ◽  
B Virus

The hepatitis B virus (HBV) X protein (pX) is capable of activating transcription regulated by viral and cellular promoters containing binding sites for different transcription factors, including AP1. In this study we have analyzed the mechanisms of AP1 induction by pX. The hepatitis B virus transactivator was able to activate TRE (12-O-tetradecanoylphorbol-13-acetate response element)-directed transcription in different cell lines, including HepG2, HeLa, CV1, and PLC/PRF/5 cells. pX-induced AP1 activation in HepG2 cells was associated with an increase in the DNA-binding activity of c-Jun/c-Fos heterodimers, which was not dependent either on an increase in the overall amount of c-Fos and c-Jun proteins in the cells or on formation of dimers between pX and the two proteins, thus suggesting the involvement of posttranslational modifications of the transcription factor. The observation that the overexpression of c-Jun and c-Fos in the cells results in a strong augmentation of the effect of pX on TRE-directed transcription is additional evidence indicating the involvement of posttranscriptional modifications of c-Jun/c-Fos heterodimers. The increased AP1 binding observed in the presence of pX was unaffected by the protein kinase C inhibitors calphostin C and sphingosine and by the protein kinase A inhibitor HA1004, while it was almost completely blocked by staurosporine, a potent and nonspecific protein kinase inhibitor, suggesting that protein kinase C- and A-independent phosphorylation events might play a role in the phenomenon. The ability of pX also to increase TRE-directed transcription in cell lines in which AP1-binding activity is not increased (i.e., HeLa, CV1, and PLC/PRF/5 cells) suggests that pX can activate canonical TRE sites by different mechanisms as well.

scholarly journals Structure of the p53/RNA polymerase II assembly

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Shu-Hao Liou ◽  
Sameer K. Singh ◽  
Robert H. Singer ◽  
Robert A. Coleman ◽  
Wei-Li Liu
Keyword(s):  
Dna Binding ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Conformational Changes ◽  
P53 Protein ◽  
Binding Activity ◽  
Transactivation Domain ◽  
Pol Ii ◽  
Dna Binding Activity ◽  
Regulated Gene Expression

AbstractThe tumor suppressor p53 protein activates expression of a vast gene network in response to stress stimuli for cellular integrity. The molecular mechanism underlying how p53 targets RNA polymerase II (Pol II) to regulate transcription remains unclear. To elucidate the p53/Pol II interaction, we have determined a 4.6 Å resolution structure of the human p53/Pol II assembly via single particle cryo-electron microscopy. Our structure reveals that p53’s DNA binding domain targets the upstream DNA binding site within Pol II. This association introduces conformational changes of the Pol II clamp into a further-closed state. A cavity was identified between p53 and Pol II that could possibly host DNA. The transactivation domain of p53 binds the surface of Pol II’s jaw that contacts downstream DNA. These findings suggest that p53’s functional domains directly regulate DNA binding activity of Pol II to mediate transcription, thereby providing insights into p53-regulated gene expression.

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