MCB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow An author's correction has been published
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Espinoza, F. H.
Right arrow Articles by Morgan, D. O.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Espinoza, F. H.
Right arrow Articles by Morgan, D. O.

Molecular and Cellular Biology, November 1998, p. 6365-6373, Vol. 18, No. 11
0270-7306/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.

Cak1 Is Required for Kin28 Phosphorylation and Activation In Vivo

F. Hernán Espinoza,1 Alison Farrell,1 Jamison L. Nourse,1 Holly M. Chamberlin,1 Opher Gileadi,2 and David O. Morgan1,*

Departments of Physiology and Biochemistry & Biophysics, University of California, San Francisco, California 94143-0444,1 and Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot 76100, Israel2

Received 29 April 1998/Returned for modification 1 June 1998/Accepted 4 August 1998

Complete activation of most cyclin-dependent protein kinases (CDKs) requires phosphorylation by the CDK-activating kinase (CAK). In the budding yeast, Saccharomyces cerevisiae, the major CAK is a 44-kDa protein kinase known as Cak1. Cak1 is required for the phosphorylation and activation of Cdc28, a major CDK involved in cell cycle control. We addressed the possibility that Cak1 is also required for the activation of other yeast CDKs, such as Kin28, Pho85, and Srb10. We generated three new temperature-sensitive cak1 mutant strains, which arrested at the restrictive temperature with nonuniform budding morphology. All three cak1 mutants displayed significant synthetic interactions with loss-of-function mutations in CDC28 and KIN28. Loss of Cak1 function reduced the phosphorylation and activity of both Cdc28 and Kin28 but did not affect the activity of Pho85 or Srb10. In the presence of the Kin28 regulatory subunits Ccl1 and Tfb3, Kin28 was phosphorylated and activated when coexpressed with Cak1 in insect cells. We conclude that Cak1 is required for the activating phosphorylation of Kin28 as well as that of Cdc28.

* Corresponding author. Mailing address: Department of Physiology, Box 0444, University of California, San Francisco, CA 94143-0444. Phone: (415) 476-6695. Fax: (415) 476-4929. E-mail: dmorgan{at}cgl.ucsf.edu.

Molecular and Cellular Biology, November 1998, p. 6365-6373, Vol. 18, No. 11
0270-7306/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 1998 by the American Society for Microbiology. All rights reserved.