Previous Article | Next Article 
Molecular and Cellular Biology, January 2001, p. 88-99, Vol. 21, No. 1
Cell Biology Program, Memorial
Sloan-Kettering Cancer Center, New York, New York
10021,1 and Department of
Physiology, University of California, San Francisco, California
941432
Received 5 October 2000/Accepted 11 October 2000
Cyclin-dependent kinase 7 (CDK7) is the catalytic subunit of the
metazoan CDK-activating kinase (CAK), which activates CDKs, such as
CDC2 and CDK2, through phosphorylation of a conserved threonine residue
in the T loop. Full activation of CDK7 requires association with a
positive regulatory subunit, cyclin H, and phosphorylation of a
conserved threonine residue at position 170 in its own T loop. We show
that threonine-170 of CDK7 is phosphorylated in vitro by its targets,
CDC2 and CDK2, which also phosphorylate serine-164 in the CDK7 T loop,
a site that perfectly matches their consensus phosphorylation site. In
contrast, neither CDK4 nor CDK7 itself can phosphorylate the CDK7 T
loop in vitro. The ability of CDC2 or CDK2 and CDK7 to phosphorylate
each other but not themselves implies that each kinase can discriminate
among closely related sequences and can recognize a substrate site that
diverges from its usual preferred site. To understand the basis for
this paradoxical substrate specificity, we constructed a chimeric CDK
with the T loop of CDK7 grafted onto the body of CDK2. Surprisingly,
the hybrid enzyme, CDK2-7, was efficiently activated in cyclin
A-dependent fashion by CDK7 but not at all by CDK2. CDK2-7, moreover,
phosphorylated wild-type CDK7 but not CDK2. Our results suggest that
the primary amino acid sequence of the T loop plays only a minor role,
if any, in determining the specificity of cyclin-dependent CAKs for their CDK substrates and that protein-protein interactions involving sequences outside the T loop can influence substrate specificity both
positively and negatively.
0270-7306/01/$04.00+0 DOI: 10.1128/MCB.21.1.88-99.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
Reciprocal Activation by Cyclin-Dependent Kinases 2 and 7 Is Directed by Substrate Specificity Determinants outside
the T Loop
*
Corresponding author. Mailing address: Cell Biology
Program, Memorial Sloan-Kettering Cancer Center, 1275 York Ave., New
York, NY 10021. Phone: (212) 639-8912. Fax: (212) 717-3317. E-mail: r-fisher{at}ski.mskcc.org.
Molecular and Cellular Biology, January 2001, p. 88-99, Vol. 21, No. 1
0270-7306/01/$04.00+0 DOI: 10.1128/MCB.21.1.88-99.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
-
Bockstaele, L., Bisteau, X., Paternot, S., Roger, P. P.
(2009). Differential Regulation of Cyclin-Dependent Kinase 4 (CDK4) and CDK6, Evidence that CDK4 Might Not Be Activated by CDK7, and Design of a CDK6 Activating Mutation. Mol. Cell. Biol.
29: 4188-4200
[Abstract] [Full Text] -
Yang, W.-H., Heaton, J. H., Brevig, H., Mukherjee, S., Iniguez-Lluhi, J. A., Hammer, G. D.
(2009). SUMOylation Inhibits SF-1 Activity by Reducing CDK7-Mediated Serine 203 Phosphorylation. Mol. Cell. Biol.
29: 613-625
[Abstract] [Full Text] -
Ajduk, A., Ciemerych, M. A, Nixon, V., Swann, K., Maleszewski, M.
(2008). Fertilization differently affects the levels of cyclin B1 and M-phase promoting factor activity in maturing and metaphase II mouse oocytes. Reproduction
136: 741-752
[Abstract] [Full Text] -
Pei, Y., Du, H., Singer, J., St. Amour, C., Granitto, S., Shuman, S., Fisher, R. P.
(2006). Cyclin-Dependent Kinase 9 (Cdk9) of Fission Yeast Is Activated by the CDK-Activating Kinase Csk1, Overlaps Functionally with the TFIIH-Associated Kinase Mcs6, and Associates with the mRNA Cap Methyltransferase Pcm1 In Vivo. Mol. Cell. Biol.
26: 777-788
[Abstract] [Full Text] -
Fisher, R. P.
(2005). Secrets of a double agent: CDK7 in cell-cycle control and transcription. J. Cell Sci.
118: 5171-5180
[Abstract] [Full Text] -
Lee, K. M., Miklos, I., Du, H., Watt, S., Szilagyi, Z., Saiz, J. E., Madabhushi, R., Penkett, C. J., Sipiczki, M., Bahler, J., Fisher, R. P.
(2005). Impairment of the TFIIH-associated CDK-activating Kinase Selectively Affects Cell Cycle-regulated Gene Expression in Fission Yeast. Mol. Biol. Cell
16: 2734-2745
[Abstract] [Full Text] -
Bondi, J, Husdal, A, Bukholm, G, Nesland, J M, Bakka, A, Bukholm, I R K
(2005). Expression and gene amplification of primary (A, B1, D1, D3, and E) and secondary (C and H) cyclins in colon adenocarcinomas and correlation with patient outcome. J. Clin. Pathol.
58: 509-514
[Abstract] [Full Text] -
Boudeau, J., Scott, J. W., Resta, N., Deak, M., Kieloch, A., Komander, D., Hardie, D. G., Prescott, A. R., van Aalten, D. M. F., Alessi, D. R.
(2004). Analysis of the LKB1-STRAD-MO25 complex. J. Cell Sci.
117: 6365-6375
[Abstract] [Full Text] -
Moisan, A., Larochelle, C., Guillemette, B., Gaudreau, L.
(2004). BRCA1 Can Modulate RNA Polymerase II Carboxy-Terminal Domain Phosphorylation Levels. Mol. Cell. Biol.
24: 6947-6956
[Abstract] [Full Text] -
Paternot, S., Coulonval, K., Dumont, J. E., Roger, P. P.
(2003). Cyclic AMP-dependent Phosphorylation of Cyclin D3-bound CDK4 Determines the Passage through the Cell Cycle Restriction Point in Thyroid Epithelial Cells. J. Biol. Chem.
278: 26533-26540
[Abstract] [Full Text] -
Ukomadu, C., Dutta, A.
(2003). Inhibition of cdk2 Activating Phosphorylation by Mevastatin. J. Biol. Chem.
278: 4840-4846
[Abstract] [Full Text] -
DeFilippis, R. A., Goodwin, E. C., Wu, L., DiMaio, D.
(2002). Endogenous Human Papillomavirus E6 and E7 Proteins Differentially Regulate Proliferation, Senescence, and Apoptosis in HeLa Cervical Carcinoma Cells. J. Virol.
77: 1551-1563
[Abstract] [Full Text]
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»