Article abstract
Nature Chemical Biology 4, 25 - 32 (2008)
Published online: 25 November 2007 | doi:10.1038/nchembio.2007.52
Molecular basis of cyclin-CDK-CKI regulation by reversible binding of an inositol pyrophosphate
Young-Sam Lee1, Kexin Huang2, Florante A Quiocho2 & Erin K O'Shea1
Abstract
When Saccharomyces cerevisiae cells are starved of inorganic phosphate, the Pho80-Pho85 cyclin–cyclin-dependent kinase (CDK) is inactivated by the Pho81 CDK inhibitor (CKI). The regulation of Pho80-Pho85 is distinct from previously characterized mechanisms of CDK regulation: the Pho81 CKI is constitutively associated with Pho80-Pho85, and a small-molecule ligand, inositol heptakisphosphate (IP7), is required for kinase inactivation. We investigated the molecular basis of the IP7- and Pho81-dependent Pho80-Pho85 inactivation using electrophoretic mobility shift assays, enzyme kinetics and fluorescence spectroscopy. We found that IP7 interacts noncovalently with Pho80-Pho85-Pho81 and induces additional interactions between Pho81 and Pho80-Pho85 that prevent substrates from accessing the kinase active site. Using synthetic peptides corresponding to Pho81, we define regions of Pho81 responsible for constitutive Pho80-Pho85 binding and IP7-regulated interaction and inhibition. These findings expand our understanding of the mechanisms of cyclin-CDK regulation and of the biochemical mechanisms of IP7 action.
- Howard Hughes Medical Institute, Harvard University, Department of Molecular and Cellular Biology and Department of Chemistry and Chemical Biology, Faculty of Arts and Sciences Center for Systems Biology, 7 Divinity Avenue, Cambridge, Massachusetts 02138, USA.
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Room T-517, Houston, Texas 77030, USA.
Correspondence to: Erin K O'Shea1 e-mail: erin_oshea@harvard.edu
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated.
NEWS AND VIEWS
IP 7 guards the CDK gateNature Chemical Biology News and Views (01 Jan 2008)
Second messenger control of chromatin remodelingNature Structural Biology News and Views (01 Feb 2003)
RESEARCH
Identification of the PIP 2 -binding site on Kir6.2 by molecular modelling and functional analysisThe EMBO Journal Article (22 Aug 2007)
D-type cyclins repress transcriptional activation by the v-Myb but not the c-Myb DNA-binding domainThe EMBO Journal Article (01 Jan 1998)
See all 4 matches for Research
