NKG2D is an activating receptor (transmembrane protein) belonging to the NKG2 family of C-type lectin-like receptors.[5] NKG2D is encoded by KLRK1 (killer cell lectin like receptor K1) gene which is located in the NK-gene complex (NKC) situated on chromosome 6 in mice[6] and chromosome 12 in humans.[7] In mice, it is expressed by NK cells, NK1.1+ T cells, γδ T cells, activated CD8+ αβ T cells and activated macrophages.[8] In humans, it is expressed by NK cells, γδ T cells and CD8+ αβ T cells.[9] NKG2D recognizes induced-self proteins from MIC and RAET1/ULBP families which appear on the surface of stressed, malignant transformed, and infected cells.[10]
^Brown MG, Fulmek S, Matsumoto K, Cho R, Lyons PA, Levy ER, et al. (May 1997). "A 2-Mb YAC contig and physical map of the natural killer gene complex on mouse chromosome 6". Genomics. 42 (1): 16–25. doi:10.1006/geno.1997.4721. PMID9177771.
^Yabe T, McSherry C, Bach FH, Fisch P, Schall RP, Sondel PM, Houchins JP (1993). "A multigene family on human chromosome 12 encodes natural killer-cell lectins". Immunogenetics. 37 (6): 455–60. doi:10.1007/BF00222470. PMID8436421. S2CID27350036.
^Bauer S, Groh V, Wu J, Steinle A, Phillips JH, Lanier LL, Spies T (July 1999). "Activation of NK cells and T cells by NKG2D, a receptor for stress-inducible MICA". Science. 285 (5428): 727–9. doi:10.1126/science.285.5428.727. PMID10426993.