Description General description Major histocompatibility complex class I-related gene protein (UniProt: Q95460; also known as MHC class I-related gene protein, Class I histocompatibility antigen-like protein, MR1) is encoded by the MR1 gene (Gene ID: 3140) in human. MR1 is a single-pass membrane protein that is ubiquitous in its distribution and can heterodimerize with B2M. It serves as an antigen-presenting molecule specialized in presenting microbial vitamin B metabolites. It is involved in the development and expansion of a small population of T-cells expressing an invariant T-cell receptor alpha chain known as mucosal-associated invariant T-cells (MAIT). MAIT lymphocytes are preferentially located in the gut lamina propria and may be involved in monitoring commensal flora or serve as a distress signal. MR1-restricted T cells can discriminate between microbes in a TCR-dependent manner. However, these cells are shown to be severely reduced in circulation in subjects with chronic HIV-1 infection. MR1 is synthesized with a signal peptide (aa 1-22), which is subsequently cleaved off in the mature form. The mature form has an extracellular domain (aa 23-302), a transmembrane domain (aa-303-323), and a short cytoplasmic tail (aa 324-341). Its ligand binding region is localized to amino acids 23-201. Five different isoforms of MR1 have been described that are produced by alternative splicing. (Ref.: Young, MH et al., (2013). PLOS one 8(1); e53789; Leeansyah, E., et al. (2013). Blood. 121(7); 1124-1135). Specificity Clone 26.5 specifically detects Major histocompatibility complex class I-related gene protein (MR1). It targets an epitope with in the extracellular domain. Immunogen Epitope: extracellular domain GST-tagged recombinant fragment corresponding to 280 amino acids from the extracellular domain of human MHC class I-related gene protein. Application Anti-MR1, clone 26.5, Cat. No. MABF2075, is a mouse monoclonal antibody that detects MHC class I-related gene protein and has been tested for use in Flow Cytometry, Function Analysis, and Immunoprecipitation. Immunoprecipitation Analysis: A representative lot immunoprecipitated MR1 in Immunoprecipitation applications (Huang, S., et. al. (2005). J Biol Chem. 280(22):21183-93). Flow Cytometry Analysis: A representative lot detected MR1 in flow cytometry applications (Huang, S., et. al. (2005). J Biol Chem. 280(22):21183-93; Gold, M.C., et. al. (2010). PLoS Biol. 8(6):e1000407; Huang, S., et. al. (2009). Proc Natl Acad Sci U S A. 106(20):8290-5). Inhibits Activity/Function Analysis: A representative lot inhibited the activation of mucosal-associated invariant T (MAIT) cells by MR1 protein. (Huang, S., et. al. (2009). Proc Natl Acad Sci U S A. 106(20):8290-5). Research Category Inflammation & Immunology Target description 39.37 kDa calculated. Physical form Format: Purified Protein G purified Purified mouse monoclonal antibody IgG2a in PBS without azide. Storage and Stability Stable for 1 year at -20°C from date of receipt. Handling Recommendations: Upon receipt and prior to removing the cap, centrifuge the vial and gently mix the solution. Aliquot into microcentrifuge tubes and store at -20°C. Avoid repeated freeze/thaw cycles, which may damage IgG and affect product performance. Disclaimer Unless otherwise stated in our catalog or other company documentation accompanying the product(s), our products are intended for research use only and are not to be used for any other purpose, which includes but is not limited to, unauthorized commercial uses, in vitro diagnostic uses, ex vivo or in vivo therapeutic uses or any type of consumption or application to humans or animals. Quality Evaluated by Flow Cytometry in MR1-transfected WT3 mouse embryonic fibroblasts. Flow Cytometry Analysis: 1 µg of this antibody detected MR1 in one million MR1-transfected WT3 mouse embryonic fibroblasts. Other Notes Concentration: Please refer to lot specific datasheet.