Identification of Two Suppressors of CSG2 Calcium Sensitivity, SCS7 and SUR2, as Genes Encoding Hydroxylases of the Sphingolipid Biosynthetic Pathway of Saccharomyces cerevisiae
Abstract
Sphingolipids are abundant constituents of the plasma membrane of many eukaryotic cell types from yeast to human and are known to function in numerous cellular metabolic processes. Sphingolipids have a wide range of structural diversity with respect to the composition of the head group and the hydroxylation state of the ceramide backbone. The biochemical significance of much of this structural variability is not well understood. The sphingolipids of the yeast Saccharomyces cerevisiae undergo the alpha-hydroxylation of the very long chain fatty acid (VLCFA) moiety of the ceramide backbone in the same manner as animal cells. Yeast sphingolipids are additionally hydroxylated on the long chain base (LCB) moiety and at a second position on the VLCFA. A connection between sphingolipid hydroxylation and calcium homeostasis in yeast is suggested by the phenotypic behavior ofthe calcium sensitive csg2 mutant and its suppressors. This mutant cannot mannosylate the sphingolipid head groups and thus over accumulates unmannosylated sphingolipids with hydroxylated ceramide backbones.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 10, 1997
- Accession Number
- AD1011647
Entities
People
- Dale A. Haak
Organizations
- Uniformed Services University of the Health Sciences