HLA-DMA
Description
The HLA-DMA (major histocompatibility complex, class II, DM alpha) is a protein-coding gene located on chromosome 6.
HLA-DMA, also known as HLA class II histocompatibility antigen, DM alpha chain, is a protein encoded by the HLA-DMA gene. It belongs to the HLA class II alpha chain paralogues and forms a heterodimer with HLA-DMB. This heterodimer is located in intracellular vesicles and plays a crucial role in peptide loading of MHC class II molecules. HLA-DMA helps release the CLIP molecule from the peptide binding site, allowing for the acquisition of antigenic peptides. Class II molecules are expressed in antigen presenting cells (APCs) such as B lymphocytes, dendritic cells, and macrophages. The alpha chain is approximately 33-35 kDa and its gene contains 5 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.
HLA-DMA plays a crucial role in the loading of peptides onto MHC class II molecules. It catalyzes the release of CLIP (class II-associated invariant chain peptide) from newly synthesized MHC class II molecules, thereby freeing the peptide binding site for the acquisition of antigenic peptides. In B-cells, the interaction between HLA-DMA and MHC class II molecules is regulated by HLA-DO.
HLA-DMA is also known as D6S222E, DMA, HLADM, RING6.
Associated Diseases
- type 1 diabetes mellitus
- schizophrenia
- sarcoidosis
- bipolar disorder
- severe combined immunodeficiency due to CTPS1 deficiency
- isolated agammaglobulinemia
- immunodeficiency 18
- common variable immunodeficiency
- severe combined immunodeficiency due to CARD11 deficiency
