HLA-DRB4
Protein-coding gene in the species Homo sapiens
From Wikipedia, the free encyclopedia
Major histocompatibility complex, class II, DR beta 4, also known as HLA-DRB4, is a human gene.[2]
| HLA-DRB4 | |||||||||||||||||||||||||||||||||||||||||||||||||||
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| Aliases | HLA-DRB4, DR-4, DR4, DRB4, HLA-DR4B, major histocompatibility complex, class II, DR beta 4, HLA-DRB4*, HLA-DRB | ||||||||||||||||||||||||||||||||||||||||||||||||||
| External IDs | GeneCards: HLA-DRB4; OMA:HLA-DRB4 - orthologs | ||||||||||||||||||||||||||||||||||||||||||||||||||
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Function
The protein encoded by this gene belongs to the HLA class II beta chain paralogues. The class II molecule is a heterodimer consisting of an alpha (DRA) and a beta chain (DRB), 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).[2]
Gene structure and polymorphisms
The beta chain is approximately 26-28 kDa. It is encoded by 6 exons, exon one encodes the leader peptide, exons 2 and 3 encode the two extracellular domains, exon 4 encodes the transmembrane domain and exon 5 encodes the cytoplasmic tail. Within the DR molecule the beta chain contains all the polymorphisms specifying the peptide binding specificities. Hundreds of DRB1 alleles have been described and typing for these polymorphisms is routinely done for bone marrow and kidney transplantation.[2]
