|CD158i||KIR2DS4 (killer cell immunoglobulin-like receptor, 2 domains, short cytoplasmic tail 4), NKAT8|
|Molecule Type||Antigen Expression||Molecular Weight|
Min / Max
|Non-lineage Restricted Molecule|
Type 1 glycoprotein
|35 / 35|
58 / 58
|CD158i is expressed on subsets of NK cells, on subsets of cytotoxic cells and some T cells. Expression on individual NK cells is complex and several members of the KIR family. The repertoire of KIR molecules varies among NK cells and is not determined solely by the HLA hapotypes.|
|MOLECULAR FAMILY NAME: Belongs to the immunoglobulin gene superfamily.|
CD158i is a single-pass type-1 304 aa glycoprotein. It contains an extracellular domain which contains 2 Ig-like C-type domains (D1 and D2), a transmembrane domain which is a charged lysine residue and a 39 aa short cytoplasmic domain with no ITIMs. KIRs with short tails are associated with NK triggering rather than inhibition. It has been shown that CD158i is expressed in 2 forms, one 35-45 kDa and the other 55-58 kDa.
POST-TRANSCRIPTIONAL MODIFICATION: No information.
POST-TRANSLATIONAL MODIFICATION: No information.
|LIGANDS AND MOLECULES ASSOCIATED WITH CD158i|
CD158i binds the HLA-C molecule.
|CD158i is involved in the activation of NK mediated cytotoxicity.|
BIOCHEMICAL ACTIVITY: No information.
DISEASE RELEVANCE AND FUNCTION OF CD158i IN INTACT ANIMAL: No information.
Killer cell immunoglobulin (Ig)-like receptors (KIR), also called killer cell inhibitory receptors, are glycoproteins expressed in natural killer (NK) cells and some T cells. The KIR family is estimated to include about 11 genes. Some members of the KIR family bind to certain HLA class I deficient cell lines. Ligation of such KIR by HLA class I molecules on target cells results in inhibition of the NK or T cell cytotoxic activity. The inhibition could be disrupted by antibodies against membrane glycoproteins on NK cells that recognized HLA- and HLA-C. Inhibitory KIRs are found in 3 distinct isoforms. KIRs that recognize HLA-C are usually monomeric glycoproteins of about 58 kDa with 2 Ig-like domains (KIR2D). KIRs that are reactive with HLA-B are approximately 70 kDa monomeric glycoproteins with 3 Ig-like domains (KIR3D). The KIR family is further subdivided into forms with short and long intracytoplasmic tails. The 1st and 2nd Ig domains in KIR2D are closely related in aa sequence to the 2nd and 3rd Ig domains in KIR3D. These 2 related Ig domains are called D1 and D2, respectively. D0 is the 1st Ig domain in KIR3D. KIR members vary in the length of the cytoplasmic tails. Most of the long cytoplasmic tails, KIR2DL and KIR3DL, deliver an inhibitory signal and carry 2 immunoreceptor tyrosine-based inhibition motifs (ITIM) which recruit and activate protein tyrosine phosphates, SHP-1 and or SHP-2. Other receptors, of about 50 kDa, with short cytoplasmic regions (KIR2DS and KIR3DS) are truncated before the 1st ITIM causing them to have no ITIMs. They are are connected to a transmembrane region which includes a lysine residue and can activate NK or T cell responses. The short tail associates with a disulfide dimer of 14 kDa. phosphoproteins called DAP12 which is also known as killer activating protein (KARAP).
Database accession numbers
Revised June 25, 2008