TY - JOUR
T1 - Requirements for Cdk7 in the Assembly of Cdk1/Cyclin B and Activation of Cdk2 Revealed by Chemical Genetics in Human Cells
AU - Larochelle, Stéphane
AU - Merrick, Karl A.
AU - Terret, Marie Emilie
AU - Wohlbold, Lara
AU - Barboza, Nora M.
AU - Zhang, Chao
AU - Shokat, Kevan M.
AU - Jallepalli, Prasad V.
AU - Fisher, Robert P.
N1 - Funding Information:
We thank D. Morgan (University of California, San Francisco) for cyclin B and NDPK expression vectors, S. Keeney for critical review of the manuscript, and H. Hochegger and S. Takeda (Kyoto University) for communicating their prepublication results. This work was supported by a postdoctoral fellowship of the Deutsche Forschungsgemeinschaft to L.W. and by U.S. National Institutes of Health grants GM56985 to R.P.F., CA107342 to P.V.J., and EB001987 to K.M.S.
PY - 2007/3/23
Y1 - 2007/3/23
N2 - Cell division is controlled by cyclin-dependent kinases (CDKs). In metazoans, S phase onset coincides with activation of Cdk2, whereas Cdk1 triggers mitosis. Both Cdk1 and -2 require cyclin binding and T loop phosphorylation for full activity. The only known CDK-activating kinase (CAK) in metazoans is Cdk7, which is also part of the transcription machinery. To test the requirements for Cdk7 in vivo, we replaced wild-type Cdk7 with a version sensitive to bulky ATP analogs in human cancer cells. Selective inhibition of Cdk7 in G1 prevents activation (but not formation) of Cdk2/cyclin complexes and delays S phase. Inhibiting Cdk7 in G2 blocks entry to mitosis and disrupts Cdk1/cyclin B complex assembly, indicating that the two steps of Cdk1 activation-cyclin binding and T loop phosphorylation-are mutually dependent. Therefore, by combining chemical genetics and homologous gene replacement in somatic cells, we reveal different modes of CDK activation by Cdk7 at two distinct execution points in the cell cycle.
AB - Cell division is controlled by cyclin-dependent kinases (CDKs). In metazoans, S phase onset coincides with activation of Cdk2, whereas Cdk1 triggers mitosis. Both Cdk1 and -2 require cyclin binding and T loop phosphorylation for full activity. The only known CDK-activating kinase (CAK) in metazoans is Cdk7, which is also part of the transcription machinery. To test the requirements for Cdk7 in vivo, we replaced wild-type Cdk7 with a version sensitive to bulky ATP analogs in human cancer cells. Selective inhibition of Cdk7 in G1 prevents activation (but not formation) of Cdk2/cyclin complexes and delays S phase. Inhibiting Cdk7 in G2 blocks entry to mitosis and disrupts Cdk1/cyclin B complex assembly, indicating that the two steps of Cdk1 activation-cyclin binding and T loop phosphorylation-are mutually dependent. Therefore, by combining chemical genetics and homologous gene replacement in somatic cells, we reveal different modes of CDK activation by Cdk7 at two distinct execution points in the cell cycle.
KW - CELLCYCLE
UR - http://www.scopus.com/inward/record.url?scp=33947424005&partnerID=8YFLogxK
U2 - 10.1016/j.molcel.2007.02.003
DO - 10.1016/j.molcel.2007.02.003
M3 - Article
C2 - 17386261
AN - SCOPUS:33947424005
SN - 1097-2765
VL - 25
SP - 839
EP - 850
JO - Molecular Cell
JF - Molecular Cell
IS - 6
ER -