A carboxyl-terminal cysteine residue is required for palmitic acid binding and biological activity of the ras-related yeast YPT1 protein.
AUTOR(ES)
Molenaar, C M
RESUMO
The Saccharomyces cerevisiae YPT1 gene codes for a ras-like, guanine nucleotide-binding protein which is essential for cell viability. The functional significance of two consecutive cysteines at the very carboxyl-terminal end of this protein and in ypt homologues of other eukaryotic species was examined. YPT1 gene mutations were generated that either led to substitutions by serine or the deletion of one or both C-terminal cysteines. The consequences of the mutations were checked in cells after replacing the wild type with the mutant genes. It was found that as long as one of the cysteines was retained, the protein was fully functional. The YPT1 protein could be labelled with [3H]palmitic acid that appeared to be bound in an ester linkage. The wild-type protein was evenly distributed between soluble and membrane-associated proteins, the palmitoylated form was predominantly in the crude membrane fraction. The mutant protein lacking the C-terminal cysteines was not palmitoylated and was exclusively found in the soluble fraction. The extension by three residues, -Val-Leu-Ser, generating a ras-typical C-terminal end, did not interfere with the mutant YPT1 protein's function although it resulted in a reduced labelling with palmitic acid.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=454423Documentos Relacionados
- The ras-related mouse ypt1 protein can functionally replace the YPT1 gene product in yeast.
- Nucleotide sequence of the mouse ypt1 gene encoding a ras-related GTP-binding protein.
- The ras-related ypt protein is an ubiquitous eukaryotic protein: isolation and sequence analysis of mouse cDNA clones highly homologous to the yeast YPT1 gene.
- Biochemical properties of the ras-related YPT protein in yeast: a mutational analysis.
- Importance of the cysteine-rich carboxyl-terminal half of V protein for Sendai virus pathogenesis.