NKG2
killer cell lectin-like receptor subfamily C, member 1 | |||||||
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Identifiers | |||||||
Symbol | KLRC1 | ||||||
Alt. symbols | NKG2, NKG2-A, NKG2-B, CD159a | ||||||
Chr. 12 p13 | |||||||
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NKG2 also known as CD159 (Cluster of Differentiation 159) is a receptor for
Gene expression
In both humans and mice, genes encoding the NKG2 family are clustered – in human genome on chromosome 12, in mouse on chromosome 6.[2] They are generally expressed on NK cells and a subset of CD8+ T cells, although the expression of NKG2D was also confirmed on γδ T cells, NKT cells, and even on some subsets of CD4+ T cells or myeloid cells. NKG2D expression can also be present on cancer cells and is proven to stimulate oncogenic bioenergetic metabolism, proliferation and metastases generation.[3]
On NK cells, NKG2 genes are expressed through the ontogeny as well as in adulthood. As about 90% of fetal NK cells express NKG2 genes, one of the proposed functions of the gene family is contribution to self-tolerance.[4] The level of expression of NKG2 genes is not constant, rather it is affected by cytokine environment (mainly interleukin-2 (IL-2), IL-7 and IL-15).[5]
For CD8+ T lymphocytes, NKG2 family expression is believed to be a marker of activated or memory T cells. The expression is triggered namely by IL-15, IL-12, IL-10 and TGF-β. CD94/NKG2 expression is shown to significantly increase the survival of T cells.[4]
Structure
NKG2 are members of the
Inhibitory molecules
Signalling
Inhibitory NKG2
DAP-10 connects to GRB2 or p85, leading to signalling through phosphoinositide 3-kinase (PI3K) and other molecules, leading to cytotoxicity.[6]
Ligands
Ligands of CD94/NKG2 heterodimeric molecules are nonclassical MHC class I molecules – Qa1b molecules in mice and HLA-E in humans. These molecules both present sequences from the digested leading peptides of classical MHC class I molecules. This enables the monitoring of classical MHC class I expression on target cells.[6]
Function
CD94/NKG2
NKG2D
See also
References
External links
- NKG2+protein at the U.S. National Library of Medicine Medical Subject Headings (MeSH)