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Aberrant processing of the WSC family and Mid2p cell surface sensors results in cell death of Saccharomyces cerevisiae O-mannosylation mutants.

Publication ,  Journal Article
Lommel, M; Bagnat, M; Strahl, S
Published in: Mol Cell Biol
January 2004

Protein O mannosylation is a crucial protein modification in uni- and multicellular eukaryotes. In humans, a lack of O-mannosyl glycans causes congenital muscular dystrophies that are associated with brain abnormalities. In yeast, protein O mannosylation is vital; however, it is not known why impaired O mannosylation results in cell death. To address this question, we analyzed the conditionally lethal Saccharomyces cerevisiae protein O-mannosyltransferase pmt2 pmt4Delta mutant. We found that pmt2 pmt4Delta cells lyse as small-budded cells in the absence of osmotic stabilization and that treatment with mating pheromone causes pheromone-induced cell death. These phenotypes are partially suppressed by overexpression of upstream elements of the protein kinase C (PKC1) cell integrity pathway, suggesting that the PKC1 pathway is defective in pmt2 pmt4Delta mutants. Congruently, induction of Mpk1p/Slt2p tyrosine phosphorylation does not occur in pmt2 pmt4Delta mutants during exposure to mating pheromone or elevated temperature. Detailed analyses of the plasma membrane sensors of the PKC1 pathway revealed that Wsc1p, Wsc2p, and Mid2p are aberrantly processed in pmt mutants. Our data suggest that in yeast, O mannosylation increases the activity of Wsc1p, Wsc2p, and Mid2p by enhancing their stability. Reduced O mannosylation leads to incorrect proteolytic processing of these proteins, which in turn results in impaired activation of the PKC1 pathway and finally causes cell death in the absence of osmotic stabilization.

Duke Scholars

Published In

Mol Cell Biol

DOI

ISSN

0270-7306

Publication Date

January 2004

Volume

24

Issue

1

Start / End Page

46 / 57

Location

United States

Related Subject Headings

  • Saccharomyces cerevisiae Proteins
  • Saccharomyces cerevisiae
  • Molecular Sequence Data
  • Membrane Proteins
  • Membrane Glycoproteins
  • Mannosyltransferases
  • Mannose
  • Intracellular Signaling Peptides and Proteins
  • Developmental Biology
  • Calcium-Binding Proteins
 

Citation

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Lommel, M., Bagnat, M., & Strahl, S. (2004). Aberrant processing of the WSC family and Mid2p cell surface sensors results in cell death of Saccharomyces cerevisiae O-mannosylation mutants. Mol Cell Biol, 24(1), 46–57. https://doi.org/10.1128/MCB.24.1.46-57.2004
Lommel, Mark, Michel Bagnat, and Sabine Strahl. “Aberrant processing of the WSC family and Mid2p cell surface sensors results in cell death of Saccharomyces cerevisiae O-mannosylation mutants.Mol Cell Biol 24, no. 1 (January 2004): 46–57. https://doi.org/10.1128/MCB.24.1.46-57.2004.
Lommel, Mark, et al. “Aberrant processing of the WSC family and Mid2p cell surface sensors results in cell death of Saccharomyces cerevisiae O-mannosylation mutants.Mol Cell Biol, vol. 24, no. 1, Jan. 2004, pp. 46–57. Pubmed, doi:10.1128/MCB.24.1.46-57.2004.

Published In

Mol Cell Biol

DOI

ISSN

0270-7306

Publication Date

January 2004

Volume

24

Issue

1

Start / End Page

46 / 57

Location

United States

Related Subject Headings

  • Saccharomyces cerevisiae Proteins
  • Saccharomyces cerevisiae
  • Molecular Sequence Data
  • Membrane Proteins
  • Membrane Glycoproteins
  • Mannosyltransferases
  • Mannose
  • Intracellular Signaling Peptides and Proteins
  • Developmental Biology
  • Calcium-Binding Proteins