MHC class I chain-related protein A (MICA)
MHC class I chain-related protein A (MICA) is a transmembrane glycoprotein that functions as a ligand for human NKG2D. MICA is absent from most cells but is frequently expressed in epithelial tumors and can be induced by bacterial and viral infections. sMICA is elevated in cervical cancer patients compared to controls. It is widely expressed with the exception of the central nervous system, where it is absent. Expressed predominantly in gastric epithelium and also in monocytes, keratinocytes, endothelial cells, fibroblasts and in the outer layer of Hassal's corpuscles within the medulla of normal thymus. In skin, expressed mainly in the keratin layers, basal cells, ducts and follicles. Also expressed in many, but not all, epithelial tumors of lung, breast, kidney, ovary, prostate and colon. In thyomas, overexpressed in cortical and medullar epithelial cells. Tumors expressing MICA display increased levels of gamma delta T-cells.
Swiss-Prot Accession Number: Q29983