QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online 16 November 2004
doi: 10.1242/jcs.01530

This Article Figures Only Full Text Full Text (PDF) All Versions of this Article: jcs.01530v1 117/25/6163    most recent Alert me when this article is cited Alert me if a correction is posted 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 Google Scholar Google Scholar Articles by Tajadura, V. Articles by Sánchez, Y. Search for Related Content PubMed PubMed Citation Articles by Tajadura, V. Articles by Sánchez, Y. Social Bookmarking                         What's this?

Schizosaccharomyces pombe Rgf3p is a specific Rho1 GEF that regulates cell wall ß-glucan biosynthesis through the GTPase Rho1p

Instituto de Microbiología Bioquímica, CSIC/Universidad de Salamanca, and Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain

^* Author for correspondence (e-mail: ysm{at}usal.es)

Accepted 10 September 2004

Rho1p regulates cell integrity by controlling the actin cytoskeleton and cell-wall synthesis. Here, we describe the cloning and characterization of rgf3⁺, a member of the Rho family of guanine nucleotide exchange factors (Rho GEFs). The rgf3⁺ gene was cloned by complementation of a mutant (ehs2-1) hypersensitive to drugs that interfere with cell-wall biosynthesis. The rgf3⁺ gene was found to be essential for cell viability and depletion of Rgf3p afforded phenotypes similar to those obtained following depletion of Rho1p. However, the cell death caused by Rgf3p depletion could be rescued by the presence of 1.2 M sorbitol, whereas depletion of Rho1 was lethal under the same conditions. We show that Rgf3p is a specific Rho1-GEF. The hypersensitivity to drugs affecting the cell wall of the ehs2-1 mutant was suppressed by overexpression of rho1⁺ but not by any of the other GTPases of the Rho family. Rgf3p interacted with the GDP-bound form of Rho1p and promoted the GDP-GTP exchange. In addition, we show that overexpression of Rgf3p produces multiseptated cells and increases ß-1,3-glucan synthase activity and the amount of cell wall ß-1,3-glucan. Rgf3p localized to the septum and the mRNA level was regulated in a cell-cycle-dependent manner peaking during septation. Our results suggest that Rgf3p acts as a positive activator of Rho1p, probably activating the Rho functions that coordinate cell-wall biosynthesis to maintain cell integrity during septation.

Key words: Cell-wall mutants, Rho GEF family, Rho1, Fission yeast, Cytokinesis

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				P. Garcia, I. Garcia, F. Marcos, G. R. de Garibay, and Y. Sanchez Fission Yeast Rgf2p Is a Rho1p Guanine Nucleotide Exchange Factor Required for Spore Wall Maturation and for the Maintenance of Cell Integrity in the Absence of Rgf1p Genetics, April 1, 2009; 181(4): 1321 - 1334. [Abstract] [Full Text] [PDF]

				P. Garcia, V. Tajadura, and Y. Sanchez The Rho1p Exchange Factor Rgf1p Signals Upstream from the Pmk1 Mitogen-activated Protein Kinase Pathway in Fission Yeast Mol. Biol. Cell, January 1, 2009; 20(2): 721 - 731. [Abstract] [Full Text] [PDF]

				A. M. Robertson and I. M. Hagan Stress-regulated kinase pathways in the recovery of tip growth and microtubule dynamics following osmotic stress in S. pombe J. Cell Sci., December 15, 2008; 121(24): 4055 - 4068. [Abstract] [Full Text] [PDF]

				M. Pinar, P. M. Coll, S. A. Rincon, and P. Perez Schizosaccharomyces pombe Pxl1 Is a Paxillin Homologue That Modulates Rho1 Activity and Participates in Cytokinesis Mol. Biol. Cell, April 1, 2008; 19(4): 1727 - 1738. [Abstract] [Full Text] [PDF]

				S. Yoshida, K. Kono, D. M. Lowery, S. Bartolini, M. B. Yaffe, Y. Ohya, and D. Pellman Polo-Like Kinase Cdc5 Controls the Local Activation of Rho1 to Promote Cytokinesis Science, July 7, 2006; 313(5783): 108 - 111. [Abstract] [Full Text] [PDF]

				Q.-W. Jin, M. Zhou, A. Bimbo, M. K. Balasubramanian, and D. McCollum A Role for the Septation Initiation Network in Septum Assembly Revealed by Genetic Analysis of sid2-250 Suppressors Genetics, April 1, 2006; 172(4): 2101 - 2112. [Abstract] [Full Text] [PDF]

				P. Garcia, V. Tajadura, I. Garcia, and Y. Sanchez Rgf1p Is a Specific Rho1-GEF That Coordinates Cell Polarization with Cell Wall Biogenesis in Fission Yeast Mol. Biol. Cell, April 1, 2006; 17(4): 1620 - 1631. [Abstract] [Full Text] [PDF]

				S. A. Rincon, B. Santos, and P. Perez Fission Yeast Rho5p GTPase Is a Functional Paralogue of Rho1p That Plays a Role in Survival of Spores and Stationary-Phase Cells Eukaryot. Cell, March 1, 2006; 5(3): 435 - 446. [Abstract] [Full Text] [PDF]

				J. L. Morrell-Falvey, L. Ren, A. Feoktistova, G. D. Haese, and K. L. Gould Cell wall remodeling at the fission yeast cell division site requires the Rho-GEF Rgf3p J. Cell Sci., December 1, 2005; 118(23): 5563 - 5573. [Abstract] [Full Text] [PDF]

				T. Mutoh, K. Nakano, and I. Mabuchi Rho1-GEFs Rgf1 and Rgf2 are involved in formation of cell wall and septum, while Rgf3 is involved in cytokinesis in fission yeast Genes Cells, December 1, 2005; 10(12): 1189 - 1202. [Abstract] [Full Text] [PDF]