Laboratory Proteolytic Systems

Being part of the anti-viral and anti-tumor immune response the ubiquitin-proteasome system plays a central role in the generation of epitopes or their precursor peptides, the latter requiring trimming by the aminopeptidases ERAP1/2. These peptides bind to MHC class I molecules and are transported to the cell surface where they are presented for recognition by cytotoxic T-lymphocytes. In addition to the classical epitopes proteasomes also generate spliced epitopes which are the results of the ligation of two proteasomal cleavage products.