Antigen-presenting molecule specialized in presenting microbial vitamin B metabolites. Involved in the development and expansion of a small population of T-cells expressing an invariant T-cell receptor alpha chain called mucosal-associated invariant T-cells (MAIT). MAIT lymphocytes are preferentially located in the gut lamina propria and therefore may be involved in monitoring commensal flora or serve as a distress signal. Expression and MAIT cell recognition seem to be ligand-dependent (By similarity).
Subcellular locations: Cell membrane, Endoplasmic reticulum