Synonyms |
CD, CELIAC 1, CELIAC1, DP beta 1 chain, DP(W4) beta chain, DPB1, DPB1_HUMAN, DQ A1, DRB1, DRB4, FLJ27088, FLJ27328, GSE, HLA class II histocompatibility antigen, HLA class II histocompatibility antigen DR 1 beta, HLA class II histocompatibility antigen DR alpha, HLA class II histocompatibility antigen DR alpha chain, HLA DP histocompatibility type beta 1 subunit, HLA DP1B, HLA DPB1, HLA DQA, HLA DQA1, HLA DQB, HLA DQB1, HLA DR1B, HLA DR3B, HLA DR4B, HLA DRA, HLA DRA1, HLA DRB1, HLA DRB3, HLA DRB4, HLA DRB5, HLA-DPB1, IDDM 1, IDDM1, Major histocompatibility complex class II DP beta 1, Major histocompatibility complex class II DQ alpha 1, Major histocompatibility complex class II DQ beta 1, Major histocompatibility complex class II DR alpha, Major histocompatibility complex class II DR beta 1, Major histocompatibility complex class II DR beta 3, Major histocompatibility complex class II DR beta 4, Major histocompatibility complex class II DR beta 5, MGC117330, MHC class II antigen DPB1, MHC class II antigen DRA, MHC class II HLA DQ alpha 1, MHC class II HLA DR beta 1, MHC class II HLA DR beta 3, MHC DPB1, MHC DQ beta, MHC HLA DPB1, MHC HLA DQ alpha |
Background |
HLA-DRA is one of the HLA class II alpha chain paralogues. This class II molecule is a heterodimer consisting of an alpha and a beta chain, both anchored in the membrane. It plays a central role in the immune system by presenting peptides derived from extracellular proteins. Class II molecules are expressed in antigen presenting cells (APC: B lymphocytes, dendritic cells, macrophages). The alpha chain is approximately 33-35 kDa and its gene contains 5 exons. Exon 1 encodes the leader peptide, exons 2 and 3 encode the two extracellular domains, and exon 4 encodes the transmembrane domain and the cytoplasmic tail. DRA does not have polymorphisms in the peptide binding part and acts as the sole alpha chain for DRB1, DRB3, DRB4 and DRB5. |