Endogenous

HLA-DRA HLA-DRA1

HLA class II histocompatibility antigen, DR alpha chain (MHC class II antigen DRA)

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. [provided by RefSeq, Jul 2008],

Disease:Genetic variations in HLA-DRA are associated with susceptibility to hepatitis B virus infection (HBV infection) [MIM:610424]. Approximately one third of all cases of cirrhosis and half of all cases of hepatocellular carcinoma can be attributed to chronic HBV infection. HBV infection may result in subclinical or asymptomatic infection, acute self-limited hepatitis, or fulminant hepatitis requiring liver transplantation.,polymorphism:The following alleles of DRA are known: DRA*0101 and DRA*0102. The sequence shown is that of DRA*0101.,similarity:Belongs to the MHC class II family.,similarity:Contains 1 Ig-like C1-type (immunoglobulin-like) domain.,subunit:Heterodimer of an alpha chain and a beta chain.,

Membrane

Expressed in professional APCs: macrophages, dendritic cells and B cells (at protein level) (PubMed:31495665, PubMed:15322540, PubMed:23783831). Expressed in thymic epithelial cells (at protein level) (PubMed:23783831).

>>Phagosome ;
>>Cell adhesion molecules ;
>>Antigen processing and presentation ;
>>Hematopoietic cell lineage ;
>>Th1 and Th2 cell differentiation ;
>>Th17 cell differentiation ;
>>Intestinal immune network for IgA production ;
>>Type I diabetes mellitus ;
>>Leishmaniasis ;
>>Toxoplasmosis ;
>>Staphylococcus aureus infection ;
>>Tuberculosis ;
>>Influenza A ;
>>Human T-cell leukemia virus 1 infection ;
>>Herpes simplex virus 1 infection ;
>>Epstein-Barr virus infection ;
>>Asthma ;
>>Autoimmune thyroid disease ;
>>Inflammatory bowel disease ;
>>Systemic lupus erythematosus ;
>>Rheumatoid arthritis ;
>>Allograft rejection ;
>>Graft-versus-host disease ;
>>Viral myocarditis