Chemical inhibition of the Pho85 cyclin-dependent kinase reveals a role in the environmental stress response

^*Howard Hughes Medical Institute, and Departments of ^†Biochemistry and Biophysics, and ^‡Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94143

Edited by Susan S. Taylor, University of California at San Diego, La Jolla, CA, and approved August 8, 2001 (received for review April 20, 2001)

Abstract

In addition to its well-established role in responding to phosphate starvation, the cyclin-dependent kinase Pho85 has been implicated in a number of other physiological responses of the budding yeast Saccharomyces cerevisiae, including synthesis of glycogen. To comprehensively characterize the range of Pho85-dependent gene expression, we used a chemical genetic approach that enabled us to control Pho85 kinase activity with a cell-permeable inhibitor and whole genome transcript profiling. We found significant phenotypic differences between the rapid loss of activity caused by inhibition and the deletion of the genomic copy of PHO85. We demonstrate that Pho85 controls the expression of not only previously identified glycogen synthetic genes, but also a significant regulon of genes involved in the cellular response to environmental stress. In addition, we show that the effects of this inhibitor are both rapid and reversible, making it well suited to the study of the behavior of dynamic signaling pathways.

Footnotes

↵ § Present address: The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037.
↵ ¶ To whom reprint requests should be addressed at: Department of Biochemistry, University of California, 513 Parnassus Avenue, Box 0448, San Francisco, CA 94143. E-mail: oshea{at}biochem.ucsf.edu.
This paper was submitted directly (Track II) to the PNAS office.
Abbreviations:

CDK,

cyclin-dependent kinase;

WT,

wild type;

GFP,

green fluorescent protein;

1-Na PP1,

4-amino-1-tert-butyl-3-(1′-naphthyl)pyrazolo[3,4-d]pyrimidine;

ESR,

environmental stress response