| 摘要 |
Molecular cloning and expression of a human gene encoding a polypeptide activator of proteasomes is disclosed. The expressed activator has an Mr of about 29,000 and is functional in activating proteasomes in vitro. In vivo this activator polypeptide is inducible with gamma -interferon in HeLa cells and occurs with a non- gamma -interferon-inducible polypeptide with an Mr of about 31,000 in a hexameric activator complex. The activator protein contains a lysine and glutamate rich region termed a KEKE motif. The KEKE motif appears to promote association between proteins and selection of peptides for presentation on MHC Class I receptors. A method for enhancing cell-mediated immunity against or tolerance to a selected immunogenic peptide is described comprising expressing activator and the selected peptide, wherein the selected peptide is adjacent to a KEKE motif, in an appropriate cell. |
