Butyrophilin Subfamily 2, Member A3 (BTN2A3)

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 and BTN3 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 BTN2A3. They obtained no full-length BTN2A3 transcript comparable to those of other BTN genes, suggesting that BTN2A3 may be a pseudogene or encode only a truncated transcript.