HLA-DRB1

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HLA-DRB1
1AQD.png
Available structures
PDB Human UniProt search: PDBe RCSB
Identifiers
Aliases HLA-DRB1, DRB1, DRw10, HLA-DR1B, HLA-DRB, SS1, HLA-DRB1, major histocompatibility complex, class II, DR beta 1
External IDs HomoloGene: 136635 GeneCards: 3123
Orthologs
Species Human Mouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_002124
NM_001243965

n/a

RefSeq (protein)

NP_002115.2
NP_001230894.1
NP_002115.2

n/a

Location (UCSC) Chr 6: 32.55 – 32.59 Mb n/a
PubMed search [1] n/a
Wikidata
View/Edit Human

HLA class II histocompatibility antigen, DRB1 beta chain is a protein that in humans is encoded by the HLA-DRB1 gene.[1] DRB1 encodes the most prevalent beta subunit of HLA-DR. Several alleles of DRB1 (shared epitope alleles)[2] are associated with an increased incidence of rheumatoid arthritis.

Function[edit]

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 to T helper cells. Class II molecules are constitutively expressed in professional antigen presenting cells (APC: B lymphocytes, dendritic cells, macrophages),[1] and could be induced in non-professional APCs.

Gene structure and polymorphisms[edit]

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.[1]

Gene expression[edit]

DRB1 is expressed at a level five times higher than its paralogues DRB3, DRB4 and DRB5. DRB1 is present in all individuals. Allelic variants of DRB1 are linked with either none or one of the genes DRB3, DRB4 and DRB5. There are 4 related pseudogenes: DRB2, DRB6, DRB7, DRB8 and DRB9.[1]

See also[edit]

References[edit]

  1. ^ a b c d "Entrez Gene: HLA-DRB1 major histocompatibility complex, class II, DR beta 1". 
  2. ^ Gregersen PK, Silver J, Winchester RJ (Nov 1987). "The shared epitope hypothesis. An approach to understanding the molecular genetics of susceptibility to rheumatoid arthritis". Arthritis and Rheumatism 30 (11): 1205–13. doi:10.1002/art.1780301102. PMID 2446635. 

Further reading[edit]

  • Turesson C, Matteson EL (Jan 2006). "Genetics of rheumatoid arthritis". Mayo Clinic Proceedings 81 (1): 94–101. doi:10.4065/81.1.94. PMID 16438485. 
  • Ahmad T, Marshall SE, Jewell D (Jun 2006). "Genetics of inflammatory bowel disease: the role of the HLA complex". World Journal of Gastroenterology 12 (23): 3628–35. PMID 16773677. 
  • Schmidt H, Williamson D, Ashley-Koch A (May 2007). "HLA-DR15 haplotype and multiple sclerosis: a HuGE review". American Journal of Epidemiology 165 (10): 1097–109. doi:10.1093/aje/kwk118. PMID 17329717.