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Evidence for the genetic interaction between the actin‐binding protein Vrp1 and the RhoGAP Rgd1 mediated through Rho3p and Rho4p in Saccharomyces cerevisiae
Author(s) -
Roumanie Olivier,
Peypouquet Marie France,
Bonneu Marc,
Thoraval Didier,
Doig François,
Crouzet Marc
Publication year - 2000
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.2000.01958.x
Subject(s) - biology , saccharomyces cerevisiae , actin cytoskeleton , microbiology and biotechnology , gtpase , gtpase activating protein , actin , cytoskeleton , mutant , myosin , gene product , genetics , gene , g protein , signal transduction , gene expression , cell
The non‐essential RGD1 gene from Saccharomyces cerevisiae encodes a protein that has been characterized in vitro as a Rho GTPase activating protein (RhoGAP) for the Rho3 and Rho4 proteins. Rgd1p, which displays a conserved FCH–coiled coil–RhoGAP domain organization, showed a patch‐like distribution in the cell, including a localization in growing buds. Using a genetic screen, we found that rgd1 Δ and vrp1 Δ mutations exhibited a synthetic lethality, thus revealing an interaction between these genes. The VRP1 product is an actin and myosin interacting protein involved in polarized growth. Using mutant forms of both Rho3 and Rho4 proteins, we provide evidence for the involvement of these two GTPases in RGD1–VRP1 co‐lethality. In addition, these results strongly argue in favour of Rho3p and Rho4p being the targets of Rgd1p RhoGAP activity in vivo . Genetic relationships between either VRP1 or RGD1 and actin cytoskeleton‐linked genes were also studied. These and other well‐established data support the idea that Vrp1, Las17, Rvs167 proteins belong to the same complex. This protein structure might act with myosins in various actin cytoskeleton‐based activities, in co‐operation with a Rho3p/Rho4p signalling pathway that is negatively regulated by Rgd1p GAP activity.