H2-Aa - histocompatibility 2, class II antigen A, alpha

Enables peptide antigen binding activity. Involved in response to interferon-gamma. Acts upstream of or within antigen processing and presentation of exogenous peptide antigen via MHC class II and positive regulation of T cell differentiation. Located in external side of plasma membrane and lysosome. Part of MHC class II protein complex. Is expressed in central nervous system; retina; and thymus primordium. Human ortholog(s) of this gene implicated in several diseases, including autoimmune disease (multiple); gastrointestinal system cancer (multiple); glomerulonephritis (multiple); hematologic cancer (multiple); and systemic scleroderma (multiple). Orthologous to several human genes including HLA-DQA1 (major histocompatibility complex, class II, DQ alpha 1). [provided by Alliance of Genome Resources, Apr 2022]