Open AccessA dominant activating mutation in the effector region of RAS abolishes IRA2 sensitivity.
Author(s) -
Kazuma Tanaka,
D R Wood,
B K Lin,
M Khalil,
Fuyuhiko Tamanoi,
John F. Can
Publication year - 1992
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.12.2.631
Subject(s) - effector , biology , mutant , gtpase , mutation , microbiology and biotechnology , adenylate kinase , gtpase activating protein , small gtpase , guanine nucleotide exchange factor , cyclase , gene , g protein , biochemistry , signal transduction , enzyme
Previously described mutations in RAS genes that cause a dominant activated phenotype affect the intrinsic biochemical properties of RAS proteins, either decreasing the intrinsic GTPase or reducing the affinity for guanine nucleotides. In this report, we describe a novel activating mutation in the RAS2 gene of Saccharomyces cerevisiae that does not alter intrinsic biochemical properties of the mutant RAS2 protein. Rather, this mutation, RAS2-P41S (proline 41 to serine), which lies in the effector region of RAS, is shown to abolish the ability of the IRA2 protein to stimulate the GTPase activity of the mutant RAS protein. This mutation also modestly reduced the ability of the mutant protein to stimulate the target adenylate cyclase in an in vitro assay, although in vivo the phenotypes it induced suggest that it retains potency in stimulation of adenylate cyclase. Our results demonstrate that although the effector region of RAS appears to be important for interaction with both target effector and negative regulators of RAS, it is possible to eliminate negative regulator responsiveness and retain potency in effector stimulation.