Enables peptide antigen binding activity. Acts upstream of or within several processes, including antigen processing and presentation of endogenous peptide antigen via MHC class I via ER pathway, TAP-dependent; antigen processing and presentation of exogenous peptide antigen via MHC class I; and positive regulation of T cell mediated cytotoxicity. Located in external side of plasma membrane. Is expressed in several structures, including brain; genitourinary system; hemolymphoid system gland; liver; and retina. Used to study myositis. Human ortholog(s) of this gene implicated in several diseases, including artery disease (multiple); asthma (multiple); autoimmune disease (multiple); eye disease (multiple); and inner ear disease (multiple). Orthologous to several human genes including HLA-A (major histocompatibility complex, class I, A); HLA-B (major histocompatibility complex, class I, B); and HLA-C (major histocompatibility complex, class I, C).
