Genetic dissection of the early stages of protein secretion in yeast

The earliest events in the export of secretory proteins from eukaryotic cells are their insertion into and transport across the membrane of the endoplasmic reticulum, followed by signal peptide cleavage and transfer of core oligosaccharides to specific asparagine residues. Much has been learned through reconstitution of these processes in vitro using cell-free extracts prepared from mammalian and yeast cells. Now, a combination of genetic, molecular and biochemical approaches are being employed to study the early stages of protein secretion in the yeast Saccharomyces cerevisiae.