University of California, Berkeley
Election Year: 1992
Primary Section: 22, Cellular and Developmental Biology
Secondary Section: 21, Biochemistry
Membership Type: Member
Protein secretion is a fundamental and evolutionarily conserved process in eukaryotic cells. I have studied this process in baker's yeast by taking advantage of facile genetic and molecular cloning techniques and biochemical characterization. My laboratory has identified genes and gene products that are implicated in the early phases of protein secretion. We discovered new membrane proteins that form a complex that allows secretory proteins, which generally are water soluble, to pass through a water-insoluble membrane. The proteins implicated in this process may be extracted from membranes using mild detergents and then reconstituted into artificial membranes that reproduce the translocation process. We have also discovered a large and complex family of genes that governs the intracellular movement of proteins contained within membrane-enclosed particles. This phase of the secretory pathway has also been reproduced in a cell-free system and has been shown to rely on the gene products that are required in living cells. Other phases of the yeast life cycle in which two nuclei fuse to form a diploid nucleus or a single nucleus divides to form daughter nuclei have been reproduced with isolated membranes. The combination of genetic and biochemical approaches offers the prospect that each of the protein molecules involved in the secretory and nuclear fusion pathways may be isolated in pure form and examined in simplified reactions.