Killer Cell Lectin-like Receptor

Killer Cell lectin-Like Receptor Subfamily K, Member 1 (KLRK1) is an activating receptor which has recently generated considerable interest. The most fascinating of these, are a couple of closely related proteins known as MICA and MICB. These are cell-surface molecules distantly related to MHC class I proteins, and their genes have elements of heat shock promoters. Thus, MICA and MICB are expressed in the course of cell stress and are up-regulated in tumor cells and during viral infections. This receptor-ligand combination has a crucial role in the immune response to various pathologies.

Killer Cell Lectin-like Receptor Subfamily G, Member 1 (KLRG1) is a member of the killer cell lectin-like receptor (KLR) family, which is a group of transmembrane proteins preferentially expressed in NK cells. Natural killer (NK) cells are lymphocytes which mediate lysis of certain tumor cells and virus-infected cells without previous activation. NK cells can also regulate specific humoral and cell-mediated immunity. The cell surface expression of KLRG1 is up-regulated by MHC class I molecules expression.

Killer cell lectin-like receptor subfamily F member 1, aka KLRF1, is a member of the C-type lectin family. KLRF1, an activating homodimeric C-type lectin-like receptor (CTLR), is expressed on nearly all natural killer (NK) cells and stimulates their cytoxicity and cytokine release. Killer cell lectin-like receptor subfamily F member 1 works through interaction with its ligand, AICL (activation-induced C-type lectin), which is selectively expressed on myeloid cells. AICL interaction regulates the immune responses at sites of inflammation by stimulating the release of proinflammatory cytokines. Diseases associated with KLRF1 include Developmental And Epileptic Encephalopathy 76.

KLRD1, also known as Killer Cell Lectin Like Receptor D1, is expressed on the surface of natural killer cells in the innate immune system. KLRD1 functions as a receptor for the recognition of MHC class I HLA-E molecules by NK cells and some cytotoxic T-cells. KLRD1 can create disulfide-bonded heterodimer with NKG2 family members. CD94 & NKG2 complex interacts with (HLA)-E, Human Leukocyte Antigen on target cells on the surface of natural killer cells.

KLRC3 belongs to the NKG2 group that can be found mostly in natural killer (NK) cells and encodes a family of transmembrane proteins known for their C-type lectin domain and their type II membrane orientation (extracellular C terminus). The NKG2 gene family is situated inside the NK complex, a region which has quite a few C-type lectin genes mostly expressed on NK cells.

KLRC2 has a part as a receptor for the recognition of MHC class I HLA-E molecules by NK cells and some cytotoxic T-cells. The group, designated KLRC (NKG2) are expressed mainly in natural killer (NK) cells and encodes a family of transmembrane proteins categorized by a type II membrane orientation (extracellular C terminus) and the presence of a C-type lectin domain. The KLRC (NKG2) gene family is situated inside the NK complex, a region which holds a few C-type lectin genes specially expressed on NK cells. KLRC2 alternative splice variants are known but their full-length nature is yet to be determined.

Killer Cell Lectin-Like Receptor Subfamily C, Member 1 (KLRC1) is a part of the killer cell lectin-like receptor family. KLRC1 functions as a receptor for the detection of MHC class I HLA-E molecules by NK cells and some cytotoxic T-cells. KLRC1 is also connects with CD94 and is expressed on NK cells and some activated T cell.

KLRB1 has an inhibitory role on natural killer (NK) cells cytotoxicity which are lymphocytes who facilitate cytotoxicity and secrete cytokines subsequent to immune stimulation. Some genes of the C-type lectin superfamily, like the rodent NKRP1 family of glycoproteins, are expressed by NK cells and take part in NK cell function regulation. KLRB1 holds an extracellular domain with a few characteristic motifs of C-type lectins, a transmembrane domain, and a cytoplasmic domain. Due to its external C terminus KLRB1 is considered to be a type II membrane protein.

KLRB1 has an inhibitory role on natural killer (NK) cells cytotoxicity which are lymphocytes who facilitate cytotoxicity and secrete cytokines subsequent to immune stimulation. Some genes of the C-type lectin superfamily, like the rodent NKRP1 family of glycoproteins, are expressed by NK cells and take part in NK cell function regulation. KLRB1 holds an extracellular domain with a few characteristic motifs of C-type lectins, a transmembrane domain, and a cytoplasmic domain. Due to its external C terminus KLRB1 is considered to be a type II membrane protein.