BTN1A1 (Butyrophilin Subfamily 1 Member A1) is a Protein Coding gene. Among its related pathways are T Cell Co-Signaling Pathway: Ligand-Receptor Interactions. GO annotations related to this gene include receptor activity. An important paralog of this gene is BTNL8. Butyrophilin is the major protein associated with fat droplets in the milk. It is a member of the immunoglobulin superfamily. It may have a cell surface receptor function.
May function in the secretion of milk-fat droplets. May act as a specific membrane-associated receptor for the association of cytoplasmic droplets with the apical plasma membrane (By similarity). Inhibits the proliferation of CD4 and CD8 T-cells activated by anti-CD3 antibodies, T-cell metabolism and IL2 and IFNG secretion (By similarity). Butyrophilin subfamily 1 member A1 is a protein that in humans is encoded by the BTN1A1 gene. Btn1a1 regulates the amount of lipids and size of droplets expressed in milk. When the gene is compromised in laboratory mice, approximately half the pups died within the first 20 days and the remainder were significantly under-weight. Butyrophilin (Btn) genes constitute a subgroup of at least 10 genes in the Ig superfamily identified in human, mouse, cow, goat and other species. The eponymous Btn gene (BTN1A1 in humans; Btn1a1 in mouse) is highly expressed in the secretory epithelium of the mammary gland during lactation. Other homologues are predominantly expressed in skeletal muscle and the intestine and erythroid cells. In contrast, BTN2A1 and 2 and BTN3A1, 2, and 3 are widely expressed in many tissues, suggesting that the structural domains of Btn proteins may have both universal and tissue-specific functions.