FIRST CHARACTERIZATION OF THE GENE RGD1 IN THE YEAST SACCHAROMYCES-CEREVISIAE

We identified the ORF YB R2 60e during systematic sequencing of one re gion of chromosome II of Saccharomyces cerevisiae. This ORF encodes a putative protein of 666 aa, of which the C-terminal part of the deduce d amino acid sequence resembles human and yeast Rho/Rac GTPase activat ing proteins (GAP). An initial study is reported in the paper. This ge ne was expressed in haploid and diploid cells and was called RGD1 for related GAP domain 1. Inactivation of RGD1 was carried out and phenoty pic analysis of the mutant strain revealed only a slight viability def ect when cells grown in minimal medium were close to stationary phase. Northern and western analyses showed that the RGD1 transcript and the corresponding protein were still abundant in cells cultivated in YNB during the stationary phase. No functional link seems to exist with th e highly conserved GTPase Cdc42 involved in cytoskeletal polarization and cell polarity. ((C) Academie des sciences/Elsevier, Paris.).