Involvement of long chain fatty acid elongation in the trafficking of secretory vesicles in yeast

• Published in: The Journal of cell biology 1998-11, Vol.143 (5), p.1167-1182
• Main Authors: David, D. (Weizmann Institute of Science, Rehovot, Israel.), Sundarababu, S, Gerst, J.E
• Format: Article
• Language: English
• Subjects: ACIDE GRAS; ACIDOS GRASOS; Alleles; AMINO ACID SEQUENCES; BETA-FRUCTOFURANOSIDASE; BINDING PROTEINS; Biological Transport, Active; CARBOXYPEPTIDASES; Carboxypeptidases - metabolism; Cathepsin A; CELL MEMBRANES; Cells; Cellular biology; Ceramides; Ceramides - biosynthesis; CHEMICAL COMPOSITION; CITOPLASMA; Cloning, Molecular; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; CYTOPLASM; CYTOPLASME; ENDOPLASMIC RETICULUM; Endoplasmic Reticulum - metabolism; EXOCYTOSIS; FATTY ACIDS; Fatty Acids - biosynthesis; FRUCTOFURANOSIDASA; FRUCTOFURANOSIDASE; Fungal Proteins - genetics; Fungal Proteins - metabolism; GENBANK/AF011409; GENBANK/AF012655; GENE; Gene Deletion; GENES; Genes, Fungal; Genetic mutation; Glycoside Hydrolases - metabolism; IMMUNOCYTOCHEMISTRY; IMMUNOLOGIE; IMMUNOLOGY; INMUNOLOGIA; LIPOGENESE; LIPOGENESIS; Lymphocytes; MEMBRANAS CELULARES; MEMBRANE CELLULAIRE; Membrane Glycoproteins - metabolism; Membrane Proteins - genetics; Membrane Proteins - metabolism; Microscopy, Electron; MOLECULAR SEQUENCE DATA; MUTANT; MUTANTES; MUTANTS; Mutation; NUCLEOTIDE SEQUENCE; Organelles - metabolism; Organelles - ultrastructure; PEPTIDASAS; PEPTIDASE; PEPTIDASES; Plasmids; PROTEINAS; PROTEINAS AGLUTINANTES; PROTEINE; PROTEINE DE LIAISON; PROTEINS; R-SNARE Proteins; RECEPTORS; RETICULO ENDOPLASMATICO; RETICULUM ENDOPLASMIQUE; SACCHAROMYCES CEREVISIAE; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae - ultrastructure; Saccharomyces cerevisiae Proteins; SECRECION; SECRETION; SECRETORY GRANULES; Secretory vesicles; SECUENCIA NUCLEOTIDICA; SEQUENCE NUCLEOTIDIQUE; SFINGOLIPIDOS; SNARE Proteins; SPHINGOLIPIDE; SPHINGOLIPIDS; Sphingolipids - biosynthesis; VBM1 GENE; VBM2 GENE; Vesicular Transport Proteins; Yeast; Yeasts
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.143.5.1167

Members of the synaptobrevin/VAMP family of v-SNAREs are thought to be essential for vesicle docking and exocytosis in both lower and higher eukaryotes. Here, we describe yeast mutants that appear to bypass the known v-SNARE requirement in secretion. Recessive mutations in either VBM1 or VBM2, which encode related ER-localized membrane proteins, allow yeast to grow normally and secrete in the absence of Snc v-SNAREs. These mutants show selective alterations in protein transport, resulting in the differential trafficking and secretion of certain protein cargo. Yet, processing of the vacuolar marker, carboxypeptidase Y, and the secreted protein, invertase, appear normal in these mutants indicating that general protein trafficking early in the pathway is unaffected. Interestingly, VBM1 and VBM2 are allelic to ELO3 and ELO2, two genes that have been shown recently to mediate the elongation of every long chain fatty acids and subsequent ceramide and inositol sphingolipid synthesis. Thus, the v-SNARE requirement in constitutive exocytosis is abrogated by mutations in early components of the secretory pathway that act at the level of lipid synthesis to affect the ability of secretory vesicles to sort and deliver protein cargo.