ULBP1 explained

UL16 binding protein 1 (ULBP1) is a cell surface glycoprotein encoded by ULBP1 gene located on the chromosome 6.^{[1] [2]} ULBP1 is related to MHC class I molecules, but its gene maps outside the MHC locus. The domain structure of ULBP1 differs significantly from those of conventional MHC class I molecules. It does not contain the α3 domain and the transmembrane segment. ULBP1 is thus composed of only the α1α2 domain which is linked to the cell membrane by the GPI anchor. It functions as a stress-induced ligand for NKG2D receptor. ULBP1 is, for example, upregulated during HCMV infection.^[3] Binding of HCMV-encoded UL16 glycoprotein to ULBP1 interferes with cell surface localization of ULBP1; this represents another mechanism by which HCMV-infected cells might escape the immune system.

Further reading

• Cerwenka A, Lanier LL . NKG2D ligands: unconventional MHC class I-like molecules exploited by viruses and cancer . Tissue Antigens . 61 . 5 . 335–43 . May 2003 . 12753652 . 10.1034/j.1399-0039.2003.00070.x .
• Steinle A, Li P, Morris DL, Groh V, Lanier LL, Strong RK, Spies T . Interactions of human NKG2D with its ligands MICA, MICB, and homologs of the mouse RAE-1 protein family . Immunogenetics . 53 . 4 . 279–87 . 2001 . 11491531 . 10.1007/s002510100325 . 33695596 .
• Sutherland CL, Chalupny NJ, Schooley K, VandenBos T, Kubin M, Cosman D . UL16-binding proteins, novel MHC class I-related proteins, bind to NKG2D and activate multiple signaling pathways in primary NK cells . Journal of Immunology . 168 . 2 . 671–9 . Jan 2002 . 11777960 . 10.4049/jimmunol.168.2.671 . free .
• Dunn C, Chalupny NJ, Sutherland CL, Dosch S, Sivakumar PV, Johnson DC, Cosman D . Human cytomegalovirus glycoprotein UL16 causes intracellular sequestration of NKG2D ligands, protecting against natural killer cell cytotoxicity . The Journal of Experimental Medicine . 197 . 11 . 1427–39 . Jun 2003 . 12782710 . 2193902 . 10.1084/jem.20022059 .
• Rölle A, Mousavi-Jazi M, Eriksson M, Odeberg J, Söderberg-Nauclér C, Cosman D, Kärre K, Cerboni C . Effects of human cytomegalovirus infection on ligands for the activating NKG2D receptor of NK cells: up-regulation of UL16-binding protein (ULBP)1 and ULBP2 is counteracted by the viral UL16 protein . Journal of Immunology . 171 . 2 . 902–8 . Jul 2003 . 12847260 . 10.4049/jimmunol.171.2.902 . free .
• Eleme K, Taner SB, Onfelt B, Collinson LM, McCann FE, Chalupny NJ, Cosman D, Hopkins C, Magee AI, Davis DM . Cell surface organization of stress-inducible proteins ULBP and MICA that stimulate human NK cells and T cells via NKG2D . The Journal of Experimental Medicine . 199 . 7 . 1005–10 . Apr 2004 . 15051759 . 2211882 . 10.1084/jem.20032194 .
• Bacon L, Eagle RA, Meyer M, Easom N, Young NT, Trowsdale J . Two human ULBP/RAET1 molecules with transmembrane regions are ligands for NKG2D . Journal of Immunology . 173 . 2 . 1078–84 . Jul 2004 . 15240696 . 10.4049/jimmunol.173.2.1078 . free .
• López-Soto A, Quiñones-Lombraña A, López-Arbesú R, López-Larrea C, González S . Transcriptional regulation of ULBP1, a human ligand of the NKG2D receptor . The Journal of Biological Chemistry . 281 . 41 . 30419–30 . Oct 2006 . 16901903 . 10.1074/jbc.M604868200 . free .

Notes and References

1. Cosman D, Müllberg J, Sutherland CL, Chin W, Armitage R, Fanslow W, Kubin M, Chalupny NJ . ULBPs, novel MHC class I-related molecules, bind to CMV glycoprotein UL16 and stimulate NK cytotoxicity through the NKG2D receptor . Immunity . 14 . 2 . 123–33 . Feb 2001 . 11239445 . 10.1016/S1074-7613(01)00095-4 . free .
2. Radosavljevic M, Cuillerier B, Wilson MJ, Clément O, Wicker S, Gilfillan S, Beck S, Trowsdale J, Bahram S . A cluster of ten novel MHC class I related genes on human chromosome 6q24.2-q25.3 . Genomics . 79 . 1 . 114–23 . Jan 2002 . 11827464 . 10.1006/geno.2001.6673 .
3. Rölle A, Mousavi-Jazi M, Eriksson M, Odeberg J, Söderberg-Nauclér C, Cosman D, Kärre K, Cerboni C . Effects of human cytomegalovirus infection on ligands for the activating NKG2D receptor of NK cells: up-regulation of UL16-binding protein (ULBP)1 and ULBP2 is counteracted by the viral UL16 protein . en . Journal of Immunology . 171 . 2 . 902–8 . Jul 2003 . 12847260 . 10.4049/jimmunol.171.2.902 . free .