KIR3DL2

Killer cell immunoglobulin-like receptor 3DL2 is a protein that in humans is encoded by the KIR3DL2 gene.^[5][6][7]

KIR3DL2
Identifiers
Aliases	KIR3DL2, CD158K, NKAT-4, NKAT4, NKAT4B, p140, 3DL2, KIR-3DL2, killer cell immunoglobulin like receptor, three Ig domains and long cytoplasmic tail 2
External IDs	OMIM: 604947; MGI: 3612791; HomoloGene: 129622; GeneCards: KIR3DL2; OMA:KIR3DL2 - orthologs
Gene location (Human) Chr. Chromosome 19 (human)[1] Band 19q13.42 Start 54,850,443 bp[1] End 54,867,207 bp[1]
Gene location (Mouse) Chr. X chromosome (mouse)[2] Band X F1|X 58.45 cM Start 135,348,856 bp[2] End 135,444,805 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in testicle granulocyte blood spleen bone marrow right lung lymph node gallbladder gonad upper lobe of left lung Top expressed in zone of skin hypothalamus spermatid placenta More reference expression data BioGPS n/a
Gene ontology Molecular function protein binding MHC class Ib protein binding Cellular component integral component of membrane plasma membrane integral component of plasma membrane membrane Biological process cellular defense response regulation of immune response negative regulation of neuron death Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 3812 245615 Ensembl ENSG00000275629 ENSG00000275838 ENSG00000277709 ENSG00000273735 ENSG00000284192 ENSG00000276004 ENSG00000278361 ENSG00000284046 ENSG00000278442 ENSG00000275416 ENSG00000275626 ENSG00000284295 ENSG00000278707 ENSG00000278758 ENSG00000278656 ENSG00000278850 ENSG00000284213 ENSG00000276424 ENSG00000284528 ENSG00000277982 ENSG00000274722 ENSG00000278726 ENSG00000275511 ENSG00000275083 ENSG00000273911 ENSG00000283975 ENSG00000276357 ENSG00000278809 ENSG00000277181 ENSG00000284384 ENSG00000283951 ENSG00000278403 ENSG00000275262 ENSG00000278710 ENSG00000275566 ENSG00000284063 ENSG00000276882 ENSG00000240403 ENSG00000276739 ENSG00000284466 ENSG00000278474 ENSG00000284381 ENSG00000288389 ENSMUSG00000057439 UniProt P43630 Q8NHI6 Q673W2 RefSeq (mRNA) NM_001242867 NM_006737 NM_177748 RefSeq (protein) NP_001229796 NP_006728 NP_001229796.1 NP_808416 Location (UCSC) Chr 19: 54.85 – 54.87 Mb Chr X: 135.35 – 135.44 Mb PubMed search [3] [4]
Wikidata
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Structure

Killer cell immunoglobulin-like receptors (KIRs) are transmembrane glycoproteins expressed on natural killer (NK) cells and subsets of T cells. KIR proteins are classified based on the number of extracellular immunoglobulin (Ig) domains—either two (2D) or three (3D)—and the length of their cytoplasmic tails: long (L) or short (S).

KIR3DL2 is a member of the 3DL family, containing three Ig-like domains and a long cytoplasmic tail. The long tail includes one or more immune tyrosine-based inhibitory motifs (ITIMs), which mediate inhibitory signaling upon ligand engagement. In contrast, KIRs with short cytoplasmic tails lack ITIMs and instead signal through association with TYRO protein tyrosine kinase binding protein, resulting in activating signals.

The KIR genes are polymorphic and highly homologous, clustered on chromosome 19q13.4 within the 1 Mb leukocyte receptor complex (LRC). The gene content of this cluster varies among haplotypes, but several "framework" genes—including KIR3DL2—are found in all haplotypes.^[7]

Function

KIR3DL2 is involved in the regulation of innate immune responses, primarily through its expression on NK cells and γδ T cells, a subset of non-MHC-I-restricted T cells.^[8]

The ligand for KIR3DL2 includes subsets of HLA class I molecules, and interaction with these ligands typically transduces inhibitory signals that suppress NK cell-mediated cytotoxicity. In addition, the protein IGSF8 (Immunoglobulin superfamily member 8) has been identified as a binding partner of KIR3DL2.^[8] Engagement of KIR3DL2 by IGSF8 functions as an immune checkpoint that inhibits NK cell cytotoxic activity, highlighting its role in immune evasion mechanisms in cancer.^[8]

See also

• Cluster of differentiation