Killer Cell Immunoglobulin Like Receptor 2DS5 (KIR2DS5)

The existence of human inhibitory natural killer (NK) cell receptors for MHC class I molecules (now designated killer cell Ig-like receptors, or KIRs), was inferred from the observation that NK cells killed HLA class I-deficient cell lines. Dohring et al. (1996) identified KIR2DS5, which they termed NKAT9. The cDNA encodes a deduced 304-amino acid protein. Sequence analysis revealed a structure similar to that described for KIR2DS2 , with an extracellular domain containing 2 Ig-like domains. The transmembrane region contains a charged lysine residue, and the cytoplasmic tail has only 39 amino acids with no ITIM (immunoreceptor tyrosine-based inhibitory motif). KIRs with short cytoplasmic tails are associated with NK cell triggering rather than inhibition. Wende et al. (1999) mapped the KIR2DS5 gene to chromosome 19q13.4 by long-range restriction analysis of YAC and PAC contigs.