Skip to main content

Regulators of pseudohyphal differentiation in Saccharomyces cerevisiae identified through multicopy suppressor analysis in ammonium permease mutant strains.

Publication ,  Journal Article
Lorenz, MC; Heitman, J
Published in: Genetics
December 1998

Nitrogen-starved diploid cells of the yeast Saccharomyces cerevisiae differentiate into a filamentous, pseudohyphal growth form. Recognition of nitrogen starvation is mediated, at least in part, by the ammonium permease Mep2p and the Galpha subunit Gpa2p. Genetic activation of the pheromone-responsive MAP kinase cascade, which is also required for filamentous growth, only weakly suppresses the filamentation defect of Deltamep2/Deltamep2 and Deltagpa2/Deltagpa2 strain. Surprisingly, deletion of Mep1p, an ammonium permease not previously thought to regulate differentiation, significantly enhances the potency of MAP kinase activation, such that the STE11-4 allele induces filamentation to near wild-type levels in Deltamep1/Deltamep1 Deltamep2/Deltamep2 and Deltamep1/Deltamep1 Deltagpa2/Deltagpa2 strains. To identify additional regulatory components, we isolated high-copy suppressors of the filamentation defect of the Deltamep1/Deltamep1 Deltamep2/Deltamep2 mutant. Multicopy expression of TEC1, PHD1, PHD2 (MSS10/MSN1/FUP4), MSN5, CDC6, MSS11, MGA1, SKN7, DOT6, HMS1, HMS2, or MEP2 each restored filamentation in a Deltamep1/Deltamep1 Deltamep2/Deltamep2 strain. Overexpression of SRK1 (SSD1), URE2, DAL80, MEP1, or MEP3 suppressed only the growth defect of the Deltamep1/Deltamep1 Deltamep2/Deltamep2 mutant strain. Characterization of these genes through deletion analysis and epistasis underscores the complexity of this developmental pathway and suggests that stress conditions other than nitrogen deprivation may also promote filamentous growth.

Duke Scholars

Published In

Genetics

DOI

ISSN

0016-6731

Publication Date

December 1998

Volume

150

Issue

4

Start / End Page

1443 / 1457

Location

United States

Related Subject Headings

  • Saccharomyces cerevisiae Proteins
  • Saccharomyces cerevisiae
  • Quaternary Ammonium Compounds
  • Phenotype
  • Mutation
  • Membrane Transport Proteins
  • Heterotrimeric GTP-Binding Proteins
  • GTP-Binding Proteins
  • GTP-Binding Protein alpha Subunits
  • Fungal Proteins
 

Citation

APA
Chicago
ICMJE
MLA
NLM

Published In

Genetics

DOI

ISSN

0016-6731

Publication Date

December 1998

Volume

150

Issue

4

Start / End Page

1443 / 1457

Location

United States

Related Subject Headings

  • Saccharomyces cerevisiae Proteins
  • Saccharomyces cerevisiae
  • Quaternary Ammonium Compounds
  • Phenotype
  • Mutation
  • Membrane Transport Proteins
  • Heterotrimeric GTP-Binding Proteins
  • GTP-Binding Proteins
  • GTP-Binding Protein alpha Subunits
  • Fungal Proteins