HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Green, R. Articles by Bussey, H. Search for Related Content PubMed PubMed Citation Articles by Green, R. Articles by Bussey, H. Agricola Articles by Green, R. Articles by Bussey, H.

A synthetic analysis of the Saccharomyces cerevisiae stress sensor Mid2p, and identification of a Mid2p-interacting protein, Zeo1p, that modulates the PKC1–MPK1 cell integrity pathway

Department of Biology, McGill University, Montreal, Quebec, Canada H3A 1B1

Correspondence
Howard Bussey
howard.bussey{at}mcgill.ca

Mid2p is a plasma membrane protein that functions in Saccharomyces cerevisiae as a sensor of cell wall stress, activating the PKC1–MPK1 cell integrity pathway via the small GTPase Rho1p during exposure to mating pheromone, calcofluor white, and heat. To examine Mid2p signalling, a global synthetic interaction analysis of a mid2 mutant was performed; this identified 11 interacting genes. These include WSC1 and ROM2, upstream elements in cell integrity pathway signalling, and FKS1 and SMI1, required for 1,3--glucan synthesis. These synthetic interactions indicate that the Wsc1p sensor acts through Rom2p to activate the Fks1p glucan synthase in a Mid2p-independent way. To further explore Mid2p signalling a two-hybrid screen was done using the cytoplasmic tail of Mid2p; this identified ZEO1 (YOL109w), encoding a 12 kDa peripheral membrane protein that localizes to the plasma membrane. Disruption of ZEO1 leads to resistance to calcofluor white and to a Mid2p-dependent constitutive phosphorylation of Mpk1p, supporting a role for Zeo1p in the cell integrity pathway. Consistent with this, zeo1-deficient cells suppress the growth defect of mutants in the Rho1p GDP–GTP exchange factor Rom2p, while exacerbating the growth defect of sac7 mutants at 37 °C. In contrast, mid2 mutants have opposing effects to zeo1 mutants, being synthetically lethal with rom2, and suppressing an 18 °C growth defect of sac7, while overexpression of MID2 rescues a rom2 37 °C growth defect. Thus, MID2 and ZEO1 appear to play reciprocal roles in the modulation of the yeast PKC1–MPK1 cell integrity pathway.

This article has been cited by other articles:

				F.-M. Lin, B. Qiao, and Y.-J. Yuan Comparative Proteomic Analysis of Tolerance and Adaptation of Ethanologenic Saccharomyces cerevisiae to Furfural, a Lignocellulosic Inhibitory Compound Appl. Envir. Microbiol., June 1, 2009; 75(11): 3765 - 3776. [Abstract] [Full Text] [PDF]

				G. Lesage and H. Bussey Cell Wall Assembly in Saccharomyces cerevisiae Microbiol. Mol. Biol. Rev., June 1, 2006; 70(2): 317 - 343. [Abstract] [Full Text] [PDF]

				H. Fernandes, O. Roumanie, S. Claret, X. Gatti, D. Thoraval, F. Doignon, and M. Crouzet The Rho3 and Rho4 small GTPases interact functionally with Wsc1p, a cell surface sensor of the protein kinase C cell-integrity pathway in Saccharomyces cerevisiae. Microbiology, March 1, 2006; 152(Pt 3): 695 - 708. [Abstract] [Full Text] [PDF]

				F. Castrejon, A. Gomez, M. Sanz, A. Duran, and C. Roncero The RIM101 Pathway Contributes to Yeast Cell Wall Assembly and Its Function Becomes Essential in the Absence of Mitogen-Activated Protein Kinase Slt2p Eukaryot. Cell, March 1, 2006; 5(3): 507 - 517. [Abstract] [Full Text] [PDF]

				S. Claret, X. Gatti, F. Doignon, D. Thoraval, and M. Crouzet The Rgd1p Rho GTPase-Activating Protein and the Mid2p Cell Wall Sensor Are Required at Low pH for Protein Kinase C Pathway Activation and Cell Survival in Saccharomyces cerevisiae Eukaryot. Cell, August 1, 2005; 4(8): 1375 - 1386. [Abstract] [Full Text] [PDF]

				D. E. Levin Cell Wall Integrity Signaling in Saccharomyces cerevisiae Microbiol. Mol. Biol. Rev., June 1, 2005; 69(2): 262 - 291. [Abstract] [Full Text] [PDF]