Our experimental approach to this question is biochemical, and is based on in vitro systems which accurately mimic protein translocation in vivo. We have developed methods for the reconstitution of translocation competent proteoliposomes from detergent extracts of ER membranes. Using this system, each biochemically discrete stage of the translocation reaction is being reconstituted, and from these studies, a molecular model for the mechanistic basis of translocation is being constructed. In our peptide trafficking studies we are focused on characterizing the role of molecular chaperones in peptide uptake and processing. Molecular chaperones are a family of peptide binding proteins that assist in protein folding and assembly, and it is now established that these proteins bind peptide substrates suitable for assembly onto MHC class I molecules.
T cell responses to the parent tumor, and thereby serve as immunotherapeutic vaccines.
Having demonstrated that both proteins are peptide binding protein, and can elicit immune responses to bound peptides, our current studies are devoted to identifying the regulation of peptide binding activity. Our experimental approach to these questions combines biochemical studies of chaperone structure and function with cell biological studies of chaperone trafficking and chaperone processing. Ribosome independent regulation of translocon composition and Sec61a conformation. Structural determinants for signal sequence function in the mammalian endoplasmic reticulum. Receptor mediated and fluid phase pathways for internalization of the ER Hsp90 chaperone GRP94 in murine macrophages.