Abstract
The tumor suppressor protein p53 acts as a transcriptional activator that can mediate cellular responses to DNA damage by inducing apoptosis and cell cycle arrest, p53 is a nuclear phosphoprotein, and phosphorylation has been proposed to be a means by which the activity of p53 is regulated. The cyclin-dependent kinase (CDK)-activating kinase (CAK) was originally identified as a cellular kinase required for the activation of a CDK-cyclin complex, and CAK is comprised of three subunits: CDK7, cyclin H, and p36(MAT1). CAK is part of the transcription factor IIH multiprotein complex, which is required for RNA polymerase II transcription and nucleotide excision repair. Because of the similarities between p53 and CAK in their involvement in the cell cycle, transcription, and repair, we investigated whether p53 could act as a substrate for phosphorylation by CAK. While CDK7-cyclin H is sufficient for phosphorylation of CDK2, we show that p36(MAT1) is required for efficient phosphorylation of p53 by CDK7-cyclin H, suggesting that p36(MAT1) can act as a substrate specificity-determining factor for CDK7- cyclin H. We have mapped a major site of phosphorylation by CAK to Ser-33 of p53 and have demonstrated as well that p53 is phosphorylated at this site in vivo. Both wild-type and tumor-derived mutant p53 proteins are efficiently phosphorylated by CAK. Furthermore, we show that p36 and p53 can interact both in vitro and in vivo. These studies reveal a potential mechanism for coupling the regulation of p53 with DNA repair and the basal transcriptional machinery.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 7220-7229 |
| Number of pages | 10 |
| Journal | Molecular and Cellular Biology |
| Volume | 17 |
| Issue number | 12 |
| State | Published - Dec 1997 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Molecular Biology
- Genetics
- Cell Biology
Cite this
p53 is phosphorylated by CDK7-cyclin H in a p36(MAT1)-dependent manner. / Ko, Linda J.; Shieh, Sheau Yann; Chen, Xinbin; Jayaraman, Lata; Tamai, Katsuyuki; Taya, Yoichi; Prives, Carol; Pan, Zhen Qiang.
In: Molecular and Cellular Biology, Vol. 17, No. 12, 12.1997, p. 7220-7229.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - p53 is phosphorylated by CDK7-cyclin H in a p36(MAT1)-dependent manner
AU - Ko, Linda J.
AU - Shieh, Sheau Yann
AU - Chen, Xinbin
AU - Jayaraman, Lata
AU - Tamai, Katsuyuki
AU - Taya, Yoichi
AU - Prives, Carol
AU - Pan, Zhen Qiang
PY - 1997/12
Y1 - 1997/12
N2 - The tumor suppressor protein p53 acts as a transcriptional activator that can mediate cellular responses to DNA damage by inducing apoptosis and cell cycle arrest, p53 is a nuclear phosphoprotein, and phosphorylation has been proposed to be a means by which the activity of p53 is regulated. The cyclin-dependent kinase (CDK)-activating kinase (CAK) was originally identified as a cellular kinase required for the activation of a CDK-cyclin complex, and CAK is comprised of three subunits: CDK7, cyclin H, and p36(MAT1). CAK is part of the transcription factor IIH multiprotein complex, which is required for RNA polymerase II transcription and nucleotide excision repair. Because of the similarities between p53 and CAK in their involvement in the cell cycle, transcription, and repair, we investigated whether p53 could act as a substrate for phosphorylation by CAK. While CDK7-cyclin H is sufficient for phosphorylation of CDK2, we show that p36(MAT1) is required for efficient phosphorylation of p53 by CDK7-cyclin H, suggesting that p36(MAT1) can act as a substrate specificity-determining factor for CDK7- cyclin H. We have mapped a major site of phosphorylation by CAK to Ser-33 of p53 and have demonstrated as well that p53 is phosphorylated at this site in vivo. Both wild-type and tumor-derived mutant p53 proteins are efficiently phosphorylated by CAK. Furthermore, we show that p36 and p53 can interact both in vitro and in vivo. These studies reveal a potential mechanism for coupling the regulation of p53 with DNA repair and the basal transcriptional machinery.
AB - The tumor suppressor protein p53 acts as a transcriptional activator that can mediate cellular responses to DNA damage by inducing apoptosis and cell cycle arrest, p53 is a nuclear phosphoprotein, and phosphorylation has been proposed to be a means by which the activity of p53 is regulated. The cyclin-dependent kinase (CDK)-activating kinase (CAK) was originally identified as a cellular kinase required for the activation of a CDK-cyclin complex, and CAK is comprised of three subunits: CDK7, cyclin H, and p36(MAT1). CAK is part of the transcription factor IIH multiprotein complex, which is required for RNA polymerase II transcription and nucleotide excision repair. Because of the similarities between p53 and CAK in their involvement in the cell cycle, transcription, and repair, we investigated whether p53 could act as a substrate for phosphorylation by CAK. While CDK7-cyclin H is sufficient for phosphorylation of CDK2, we show that p36(MAT1) is required for efficient phosphorylation of p53 by CDK7-cyclin H, suggesting that p36(MAT1) can act as a substrate specificity-determining factor for CDK7- cyclin H. We have mapped a major site of phosphorylation by CAK to Ser-33 of p53 and have demonstrated as well that p53 is phosphorylated at this site in vivo. Both wild-type and tumor-derived mutant p53 proteins are efficiently phosphorylated by CAK. Furthermore, we show that p36 and p53 can interact both in vitro and in vivo. These studies reveal a potential mechanism for coupling the regulation of p53 with DNA repair and the basal transcriptional machinery.
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UR - http://www.scopus.com/inward/citedby.url?scp=0030724673&partnerID=8YFLogxK
M3 - Article
C2 - 9372954
AN - SCOPUS:0030724673
VL - 17
SP - 7220
EP - 7229
JO - Molecular and Cellular Biology
JF - Molecular and Cellular Biology
SN - 0270-7306
IS - 12
ER -