Description
ULBP-3, also known as NKG2D ligand 3, is ligands for natural-killer group 2, member D (NKG2D) receptor. It is related to MHC class I molecules, but its gene maps outside the MHC locus. The domain structure of ULBP3 differs significantly from those of conventional MHC class I molecules. It does not contain the alpha3 domain and the transmembrane segment. ULBP3 is thus composed of only the alpha1alpha2 domain which is linked to the cell membrane by the GPI anchor. It functions as a stress-induced ligand for NKG2D receptor. In the normal hair follicle, ULBP3 is turned off. However, different studies reported its high level in alopecia areata (AA). It is also expressed on some tumor cells and have been implicated in tumor surveillance. Recombinant human ULBP-3, fused to hIgG-His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques