Butyrophilin Subfamily 3, Member A3 (BTN3A3)

The butyrophilin (BTN) genes are a group of major histocompatibility complex (MHC)-associated genes that encode type I membrane proteins with 2 extracellular immunoglobulin (Ig) domains and an intracellular B30.2 (PRYSPRY) domain. Three subfamilies of human BTN genes are located in the MHC class I region: the single-copy BTN1A1 gene and the BTN2 (e.g., BTN2A1) and BTN3 (e.g., BNT3A3) genes, which have undergone tandem duplication, resulting in 3 copies of each.By genomic sequence analysis, RT-PCR of peripheral blood leukocytes and human cell lines, and 3-prime RACE of a fetal tissue cDNA library, Rhodes et al. (2001) cloned BTN3A3. They also identified a BTN3A3 splice variant encoding a truncated protein lacking the B30.2 domain, and this variant was more abundant than the full-length form.