Robert J. Deschenes

Learn More
Palmitate modifies both peripheral and integral membrane proteins and its addition can be permanent or transient, which makes it unique among the lipid modifications of proteins. The presence of palmitate on a protein affects how the protein interacts with lipids and proteins in a membrane compartment, and the reversibility of palmitoylation allows(More)
Most Ras proteins are posttranslationally modified by a palmitoyl lipid moiety through a thioester linkage. However, the mechanism by which this occurs is not known. Here, evidence is presented that the Ras2 protein of Saccharomyces cerevisiae is palmitoylated by a Ras protein acyltransferase (Ras PAT) encoded by the ERF2 and ERF4 genes. Erf2p is a 41-kDa(More)
The Saccharomyces cerevisiae Sln1 protein is a 'two-component' regulator involved in osmotolerance. Two-component regulators are a family of signal-transduction molecules with histidine kinase activity common in prokaryotes and recently identified in eukaryotes. Phosphorylation of Sln1p inhibits the HOG1 MAP kinase osmosensing pathway via a phosphorelay(More)
Covalent lipid modifications mediate the membrane attachment and biological activity of Ras proteins. All Ras isoforms are farnesylated and carboxyl-methylated at the terminal cysteine; H-Ras and N-Ras are further modified by palmitoylation. Yeast Ras is palmitoylated by the DHHC cysteine-rich domain-containing protein Erf2 in a complex with Erf4. Here we(More)
Plasma membrane localization of Ras requires posttranslational addition of farnesyl and palmitoyl lipid moieties to a C-terminal CaaX motif (C is cysteine, a is any aliphatic residue, X is the carboxy terminal residue). To better understand the relationship between posttranslational processing and the subcellular localization of Ras, a yeast genetic screen(More)
Protein palmitoylation refers to the posttranslational addition of a 16 carbon fatty acid to the side chain of cysteine, forming a thioester linkage. This acyl modification is readily reversible, providing a potential regulatory mechanism to mediate protein-membrane interactions and subcellular trafficking of proteins. The mechanism that underlies the(More)
The isolation and characterization of MGM1, and yeast gene with homology to members of the dynamin gene family, is described. The MGM1 gene is located on the right arm of chromosome XV between STE4 and PTP2. Sequence analysis revealed a single open reading frame of 902 residues capable of encoding a protein with an approximate molecular mass of 101 kDa.(More)
A rapid and convenient method of protein purification involves creating a fusion protein with glutathione S-transferase (GST) (Smith and Johnson, Gene 67, 31-40, 1988). In this report, we describe two vectors for the conditional expression of GST fusions in Saccharomyces cerevisiae. The parent plasmid is based on a high-copy, galactose-inducible shuttle(More)
Since its discovery more than 30 years ago, protein palmitoylation has been shown to have a role in protein-membrane interactions, protein trafficking, and enzyme activity. Until recently, however, the molecular machinery that carries out reversible palmitoylation of proteins has been elusive. In fact, both enzymatic and nonenzymatic S-acylation reaction(More)