Genetic analysis of mammalian GAP expressed in yeast.
We have designed a vector to express the mammalian GAP protein in the yeast S. cerevisiae. When expressed in yeast, GAP inhibits the function of the human H-rasgly12 protein, but not that of the H-rasval12 protein, and complements the loss of IRA1. IRA1 is a yeast gene that encodes a protein with homology to GAP and acts upstream of RAS. Mammalian GAP can therefore function in yeast and interact with yeast RAS. Because expression of GAP complements ira1-mutants, we propose that GAP shares some biochemical functions with IRA1. Other studies indicate that IRA1 controls the level of RAS activity, presumably by regulating GTP hydrolysis. By analogy, we propose that GAP may play a similar role.
Ballester
R
R
Cold Spring Harbor Laboratory, New York 11724.
Michaeli
T
T
Ferguson
K
K
Xu
H P
HP
McCormick
F
F
Wigler
M
M
D003001:Cloning, Molecular / Q000379:methods; D004926:Escherichia coli / Q000235:genetics; D020690:GTPase-Activating Proteins; D015870:Gene Expression; D005796:Genes; D011905:Genes, ras; D005822:Genetic Vectors; D006358:Hot Temperature; D010957:Plasmids; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics*; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D020703:ras GTPase-Activating Proteins
D020690:GTPase-Activating Proteins; D011506:Proteins; D020703:ras GTPase-Activating Proteins