|Description:||Rabbit polyclonal antibody to HLA-DRB3.|
|Dilutions:||WB 1:500 - 1:2000, IHC 1:50 - 1:200|
|Immunogen:||Recombinant protein of human HLA-DRB3|
|Formulation:||PBS with 0.02% sodium azide, 50% glycerol, pH7.3.|
|Storage:||Store at -20℃. Avoid freeze / thaw cycles.|
Target (Information from UniProt)
|Function:||Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route, where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules, and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments, exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides, autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs, other cells of the gastrointestinal tract, such as epithelial cells, express MHC class II molecules and CD74 and act as APCs, which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen, three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs, CD74 undergoes a sequential degradation by various proteases, including CTSS and CTSL, leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells, the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal microenvironment has been implicated in the regulation of antigen loading into MHC II molecules, increased acidification produces increased proteolysis and efficient peptide loading.|
|Sequence Similarities:||Belongs to the MHC class II family.|
|Post-Translational Modification:||Ubiquitinated by MARCH1 and MARCH8 at Lys-254 leading to sorting into the endosome system and down-regulation of MHC class II.|
|Cellular Location:||Cell membrane. Endoplasmic reticulum membrane. Golgi apparatus > trans-Golgi network membrane. Endosome membrane. Lysosome membrane. Late endosome membrane.
The MHC class II complex transits through a number of intracellular compartments in the endocytic pathway until it reaches the cell membrane for antigen presentation.
|Synonyms:||DR beta 3 chain Antibody
HLA class II histocompatibility antigen Antibody
HLA class II histocompatibility antigen DR beta 3 chain Antibody
HLA class II histocompatibility antigen DRB1 7 beta chain Antibody
HLA DR3B Antibody
HLA DRB3 Antibody
Human leucocyte antigen DRB3 Antibody
Major histocompatibility complex class II DR beta 3 Antibody
MHC class II antigen DR beta 3 chain Antibody
MHC class II antigen DRB3 Antibody
MHC class II HLA DR beta 3 chain Antibody
Western blot analysis of extracts of HepG2 cell lines, using HLA-DRB3 antibody.
Immunohistochemistry of paraffin-embedded rat spleen tissue using HLA-DRB3 antibody at dilution of 1:100 (x40 lens).
Immunohistochemistry of paraffin-embedded rat kidney tissue using HLA-DRB3 antibody at dilution of 1:100 (x40 lens).
Immunohistochemistry of paraffin-embedded human tonsil tissue using HLA-DRB3 antibody at dilution of 1:100 (x40 lens).
Immunohistochemistry of paraffin-embedded human vermiform appendix tissue using HLA-DRB3 antibody at dilution of 1:100 (x40 lens).