ras-Related gene sequences identified and isolated from Saccharomyces cerevisiae

Abstract

The oncogenes of Harvey and Kirsten murine sarcoma viruses (v-ras^H and v-ras^K) and their cellular homologues (c-ras^H and c-ras^K) constitute two members of the ras gene family. Each functional member of the ras gene family encodes a 21,000 molecular weight protein (p21^ras)¹ ras genes have been detected in a wide variety of vertebrate species², including Xenopus laevis (R. E. Steele, personal communication), and in Drosophila melanogaster³. We report here the detection of ras-related genes in the yeast Saccharomyces cerevisiae, and the isolation of two ras-related molecular clones, c-ras^sc-1 and c-ras^sc-2, from the DNA of Saccharomyces. Both c-ras^sc-1 and c-ras^sc-2 hybridize specifically to probes prepared from mammalian ras DNA. Sequencing of c-ras^sc-1 reveals extensive amino acid homology between the protein encoded by c-ras^sc-1 and the p21 encoded by c-ras^H. Our studies suggest that these clones can be used to elucidate the normal cellular functions of ras-related genes in this relatively simple eukaryotic organism.