NKG2D ligand 2 (UL16-binding protein 2, NKG2DL2, N2DL-2, ALCAN-alpha, retinoic acid early transcript 1H, ULBP2, N2DL2, RAET1H, UNQ463/PRO791)

Function

• ligand for NKG2D receptor, together with at least ULBP1 & ULBP3
• ULBPs activate multiple signaling pathways in primary NK cells, resulting in production of cytokines & chemokines
• binding of ULBPs ligands to NKG2D induces Ca+2 mobilization & activation of JAK2, STAT5, ERK & PI3K kinase/Akt signal transduction pathway
• does not bind to beta2-microglobulin

Structure

• belongs to the MHC class I family
• ULBPs are unusual members of the extended MHC class 1 superfamily, because they do not contain the alpha 3 domain & they lack a transmembrane domain

Compartment

cell membrane, GPI-anchor, secreted

Expression

• expressed in fetus, but not in normal adult tissues

Pathology

• in CMV infected cells, interacts with soluble CMV glycoprotein UL16.
• interaction with UL16 blocked the interaction with NKG2D receptor, providing a mechanism by which CMV infected cells might escape the immune system
• UL16 also causes ULBP2 to be retained in the ER & cis-Golgi so that it does not reach the cell surface
• expressed in various types of cancer cell lines

More general terms

• NKG2D ligand (NKG2D)

Database

• OMIM: https://mirror.omim.org/entry/605698
• UniProt: http://www.uniprot.org/uniprot/Q9BZM5.html