Killer cell immunoglobulin-like receptor 2DL4 is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...
that in humans is encoded by the ''KIR2DL4''
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
.
Function
Killer cell immunoglobulin-like receptors
Killer-cell immunoglobulin-like receptors (KIRs), are a family of type I transmembrane glycoproteins expressed on the plasma membrane of natural killer (NK) cells and a minority of T cells. At least 15 genes and 2 pseudogenes encoding KIR map in ...
(KIRs) are transmembrane glycoproteins expressed by
natural killer cells and subsets of
CD8+ T cells
A cytotoxic T cell (also known as TC, cytotoxic T lymphocyte, CTL, T-killer cell, cytolytic T cell, CD8+ T-cell or killer T cell) is a T lymphocyte (a type of white blood cell) that kills cancer cells, cells that are infected by intracellular pa ...
.
The KIR genes are polymorphic and highly homologous and they are found in a cluster on chromosome 19q13.4 within the 1 Mb
leukocyte receptor complex
The leukocyte immunoglobulin-like receptors (LILR) are a family of receptors possessing extracellular immunoglobulin domains.
They are also known as CD85, ILTs and LIR, and can exert immunomodulatory effects on a wide range of immune cells.Damian ...
(LRC). The gene content of the KIR gene cluster varies among haplotypes, although several "framework" genes are found in all haplotypes (KIR3DL3, KIR3DP1, KIR2DL4, KIR3DL2). The KIR proteins are classified by the number of extracellular immunoglobulin domains (2D or 3D) and by whether they have a long (L) or short (S) cytoplasmic domain. KIR proteins with the long cytoplasmic domain transduce inhibitory signals upon ligand binding via an immune tyrosine-based inhibitory motif (ITIM), while KIR proteins with the short cytoplasmic domain lack the ITIM motif and instead associate with the TYRO protein tyrosine kinase binding protein to transduce activating signals. The ligands for several KIR proteins are subsets of HLA class I molecules; thus, KIR proteins are thought to play an important role in regulation of the immune response. This gene is one of the "framework" loci that is present on all haplotypes. Alternative splicing results in multiple transcript variants.
The only so far reported ligand of KIR2DL4 is the non-classical HLA class 1 gene
HLA-G, leading to the inhibition of the cytolytic NK cell function.
See also
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Cluster of differentiation
The cluster of differentiation (also known as cluster of designation or classification determinant and often abbreviated as CD) is a protocol used for the identification and investigation of cell surface molecules providing targets for immunophen ...
References
Further reading
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External links
PDBe-KBprovides an overview of all the structure information available in the PDB for Human Killer cell immunoglobulin-like receptor 2DL4 (KIR2DL4)
{{DEFAULTSORT:Kir2dl4
Clusters of differentiation
Immunoglobulin superfamily