RAM2, an essential gene of yeast, and RAM1 encode the two polypeptide components of the farnesyltransferase that prenylates a-factor and Ras proteins

He, B., Chen, P., Chen, S. Y., Vancura, K. L., Michaelis, S., Powers, S. (December 1991) RAM2, an essential gene of yeast, and RAM1 encode the two polypeptide components of the farnesyltransferase that prenylates a-factor and Ras proteins. Proceedings of the National Academy of Sciences of the United States of America, 88 (24). pp. 11373-7. ISSN 0027-8424

URL: http://www.ncbi.nlm.nih.gov/pubmed/1763050

Abstract

In the yeast Saccharomyces cerevisiae, mutations in either of two unlinked genes, RAM1 or RAM2, abolish the farnesyltransferase activity responsible for prenylation of Ras proteins and the a-factor mating pheromone. Here we report that the function of RAM1 and RAM2 genes is required for the membrane localization of Ras proteins and a-factor. The RAM2 gene was sequenced and can encode a 38-kDa protein. We examined the functional interaction of RAM2 and RAM1 by expressing the genes in Escherichia coli. Extracts derived from an E. coli strain that coexpressed RAM1 and RAM2 efficiently farnesylated a-factor peptide and Ras protein substrates. In contrast, extracts derived from E. coli strains that expressed either RAM gene alone were devoid of activity; however, when the latter extracts were mixed, protein farnesyltransferase activity was reconstituted. These results indicate that the yeast farnesyl-protein transferase is comprised of Ram1 and Ram2 polypeptides. Although Ram1 is a component of the enzyme, disruption of the RAM1 gene in yeast was not lethal, indicating that the Ram1-Ram2 farnesyltransferase is not essential for viability. In contrast, disruption of RAM2 was lethal, suggesting that Ram2 has an essential function in addition to its role with Ram1 in protein farnesylation.

Item Type: Paper
Uncontrolled Keywords: *Alkyl and Aryl Transferases Amino Acid Sequence Base Sequence Escherichia coli/genetics Fungal Proteins/*metabolism GTP-Binding Proteins/metabolism *Genes, Fungal Molecular Sequence Data Mutagenesis, Insertional Peptides/*metabolism Pheromones/metabolism Plasmids Restriction Mapping Saccharomyces cerevisiae/enzymology/*genetics Transferases/*genetics/metabolism *ras Proteins
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > G protein
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > GTP binding protein
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > G protein > Ras
organism description > yeast
CSHL Authors:
Communities: CSHL labs > Powers lab
Depositing User: Matt Covey
Date: 15 December 1991
Date Deposited: 26 Feb 2014 15:27
Last Modified: 26 Feb 2014 15:27
PMCID: PMC53137
Related URLs:
URI: http://repository.cshl.edu/id/eprint/29517

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