The yeast Rgd1p is a GTPase activating protein of the Rho3 and Rho4 proteins

Open Access
Publisher Website
Google Scholar
Abstract
The RGD1 gene, identified during sequencing of the Saccharomyces cerevisiae genome, encodes a protein with a Rho‐GTPase activating protein (GAP) domain at the carboxy‐terminal end. The Rgd1 protein showed two‐hybrid interactions with the activated forms of Rho2p, Rho3p and Rho4p. Using in vitro assays, we demonstrated that Rgd1p stimulated the GTPase activity of both Rho3p and Rho4p; no stimulation was observed on Rho2p. In addition, the rho3Δrgd1Δ double mutant exhibited a dramatic growth defect compared to the single mutants, suggesting that Rgd1p has a GAP activity in vivo. The present study allowed the identification of the first GAP of Rho3p and Rho4p.