HLA-DQB1
HLA-DQB1 (major histocompatibility complex, class II, DQ beta 1) encodes the beta chain of the HLA-DQ heterodimer, which binds peptides from antigens in the endocytic route and presents them to CD4 T-cells. It is also known as IDDM1, CELIAC1 and HLA-DQB. Browse Assay Genie's current range of HLA-DQB1 research reagents below, or read on for the biology behind the target.
HLA-DQB1 is the beta chain of an MHC class II molecule, a heterodimer of an alpha chain (DQA) and a beta chain (DQB), both anchored in the membrane. The molecule binds peptides derived from antigens that enter the endocytic route of antigen presenting cells and displays them on the cell surface for recognition by CD4 T-cells. The peptide-binding cleft accommodates peptides of 10-30 residues, which are generated mostly by lysosomal proteases and other hydrolases. Exogenous antigens must compete with endogenous material, including membrane proteins en route to degradation and peptides supplied by autophagy.
Assembly begins in the endoplasmic reticulum, where three class II heterodimers associate with a CD74 trimer to form a heterononamer. After the complex enters the endosomal and lysosomal system, CD74 is degraded sequentially by proteases including CTSS and CTSL, leaving the CLIP fragment. HLA-DM binds the alpha-beta-CLIP complex, promotes CLIP release and stabilises the class II molecule until a high-affinity peptide is bound. The peptide-loaded molecule then travels to the cell surface. In B-cells, HLA-DM activity is regulated by HLA-DO. UniProt places the protein at the cell membrane and in endoplasmic reticulum, trans-Golgi network, endosome and lysosome membranes.
The HLA-DQB1 gene belongs to the HLA class II beta chain paralogs and is part of the histocompatibility complex gene group. Class II molecules are expressed in B lymphocytes, dendritic cells and macrophages, and epithelial cells of the gastrointestinal tract can also act as antigen presenting cells. The beta chain is encoded by six exons, with exons 2 and 3 specifying the two extracellular domains. Both the alpha and beta chains of DQ carry polymorphisms that determine peptide-binding specificity, and typing for these is routinely done for bone marrow transplantation. Alternative splicing yields multiple transcript variants. The aliases IDDM1 and CELIAC1 are also used for this gene.
HLA-DQB1 forms part of the MHC class II molecule that presents endocytosed peptides to CD4 T-cells.
Its loading depends on CD74, CLIP removal by HLA-DM and the endosomal and lysosomal environment, making it a model for class II trafficking.
Polymorphisms in the DQ chains are routinely typed for bone marrow transplantation.
Gastrointestinal epithelial cells express MHC class II and CD74 and can act as antigen presenting cells, an unusual trait.
HLA-DQB1 encodes the beta chain of the HLA-DQ class II molecule. Paired with an alpha chain, it binds peptides of 10-30 residues from antigens in the endocytic route and presents them at the cell surface for recognition by CD4 T-cells.
The HGNC name is major histocompatibility complex, class II, DQ beta 1. Aliases include IDDM1, CELIAC1 and HLA-DQB. UniProt lists the protein as HLA class II histocompatibility antigen, DQ beta 1 chain. Alternative splicing gives multiple transcript variants.
Both the DQ alpha and beta chains carry polymorphisms that specify peptide-binding specificity, giving up to four different DQ molecules. Typing for these polymorphisms is routinely done for bone marrow transplantation. Check the datasheet of any product for its validated reactivity.
Other HLA class II chains, class I molecules and related histocompatibility targets with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P01920; product specifications from Assay Genie datasheets.