A carboxyl-terminal cysteine residue is required for palmitic acid binding and biological activity of the ras-related yeast YPT1 protein.

摘要: Abstract The Saccharomyces cerevisiae YPT1 gene codes for a ras-like, guanine nucleotide-binding protein which is essential cell viability. The functional significance of two consecutive cysteines at the very carboxyl-terminal end this and in ypt homologues other eukaryotic species was examined. mutations were generated that either led to substitutions by serine or deletion one both C-terminal cysteines. consequences checked cells after replacing wild type with mutant genes. It found as long retained, fully functional. could be labelled [3H]palmitic acid appeared bound an ester linkage. wild-type evenly distributed between soluble membrane-associated proteins, palmitoylated form predominantly crude membrane fraction. lacking not exclusively extension three residues, -Val-Leu-Ser, generating ras-typical end, did interfere protein's function although it resulted reduced labelling palmitic acid.