Activation of Yeast Protein Kinase C by Rho1 GTPase

doi:10.1074/jbc.271.16.9193

Activation of Yeast Protein Kinase C by Rho1 GTPase (*)

From the (1)Department of Biochemistry, Johns Hopkins University School of Public Health, Baltimore, Maryland 21205 and the
(2)Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Tokyo 113, Japan

^§To whom correspondence should be addressed:
Dept. of Biochemistry, Johns Hopkins University School of Public Health, 615 N. Wolfe St., Baltimore, MD 21205.
Tel.: 410-955-9825; Fax: 410-955-2926; levin{at}welchlink.welch.jhu.edu.

Abstract

We have investigated the role of the essential Rho1 GTPase in cell integrity signaling in budding yeast. Conditional rho1 mutants display a cell lysis defect that is similar to that of mutants in the cell integrity signaling pathway mediated by protein kinase C (Pkc1), which is suppressed by overexpression of Pkc1. rho1 mutants are also impaired in pathway activation in response to growth at elevated temperature. Pkc1 co-immunoprecipitates with Rho1 in yeast extracts, and recombinant Rho1 associates with Pkc1 in vitro in a GTP-dependent manner. Recombinant Rho1 confers upon Pkc1 the ability to be stimulated by phosphatidylserine, indicating that Rho1 controls signal transmission through Pkc1.

Footnotes

↵* This work was supported by Grant GM48533 from the National Institutes of Health, American Cancer Society Grant FRA-446 (to D. E. L.), Ministry of Education, Science, Sports and Culture of Japan Grants 07740581 and 07254203 (to Y. O.), and by grants form the Japan Society for the Promotion of Science for Japanese Junior Scientists (to H. Q.) and the Swiss National Science Foundation (to C. P. P.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵¹ The abbreviations used are:

PKC

protein kinase C

MAP

mitogen-activated protein

MAPK

mitogen-activated protein kinase

MEK

MAPK-activating kinase

MEKK

MEK-activating kinase

DAG

diacylglycerol

SRF

serum response factor

JNK

Jun NH-terminal kinase (also known as SAPK, stress-activated protein kinase)

PCR

polymerase chain reaction

HA

influenza hemagglutinin

PAGE

polyacrylamide gel electrophoresis

GST

glutathione S-transferase

PS

phosphatidylserine

PMA

phorbol myristate acetate

GS

1,3-β-glucan synthase

MBP

myelin basic protein

GTPS

guanosine 5′-O-(thiotriphosphate).
↵²C. Zhao and D. E. Levin, unpublished results.
- Received February 7, 1996.
- Revision received February 29, 1996.