Signal peptidases are the key enzymes which are responsible for removing the transient amino-terminal "signal peptides" which direct cellular proteins across specific membrane barriers. The signal peptidase to be studied in this project is the one which cleaves the signal peptide from nascent secretory or membrane proteins which are directed through the rough endoplasmic reticulum membrane. Yeast signal peptidase will be purified and characterized, and proteins associated with signal peptidase function will be isolated. Genes encoding these proteins will be cloned and used in functional studies in vivo. The role of the sec11 gene product (sec 11 is one of a series of yeast mutants with impaired secretory function) in signal peptide function will be investigated. This research will increase our understanding of the molecular basis of intracellular protein transport. This will lead not only to an enhanced understanding of fundamental life processes at the cellular level, but may also have practical applications in biotechnology, particularly in the production of genetically- engineered fermentation products.
