Yeast pseudohyphal growth is regulated by GPA2, a G protein alpha homolog.
Published
Journal Article
Pseudohyphal differentiation, a filamentous growth form of the budding yeast Saccharomyces cerevisiae, is induced by nitrogen starvation. The mechanisms by which nitrogen limitation regulates this process are currently unknown. We have found that GPA2, one of the two heterotrimeric G protein alpha subunit homologs in yeast, regulates pseudohyphal differentiation. Deltagpa2/Deltagpa2 mutant strains have a defect in pseudohyphal growth. In contrast, a constitutively active allele of GPA2 stimulates filamentation, even on nitrogen-rich media. Moreover, a dominant negative GPA2 allele inhibits filamentation of wild-type strains. Several findings, including epistasis analysis and reporter gene studies, indicate that GPA2 does not regulate the MAP kinase cascade known to regulate filamentous growth. Previous studies have implicated GPA2 in the control of intracellular cAMP levels; we find that expression of the dominant RAS2(Gly19Val) mutant or exogenous cAMP suppresses the Deltagpa2 pseudohyphal defect. cAMP also stimulates filamentation in strains lacking the cAMP phosphodiesterase PDE2, even in the absence of nitrogen starvation. Our findings suggest that GPA2 is an element of the nitrogen sensing machinery that regulates pseudohyphal differentiation by modulating cAMP levels.
Full Text
Duke Authors
Cited Authors
- Lorenz, MC; Heitman, J
Published Date
- December 1, 1997
Published In
Volume / Issue
- 16 / 23
Start / End Page
- 7008 - 7018
PubMed ID
- 9384580
Pubmed Central ID
- 9384580
International Standard Serial Number (ISSN)
- 0261-4189
Digital Object Identifier (DOI)
- 10.1093/emboj/16.23.7008
Language
- eng
Conference Location
- England