KLRB1
Description
The KLRB1 (killer cell lectin like receptor B1) is a protein-coding gene located on chromosome 12.
KLRB1, also known as NKR-P1A or CD161, is a human gene. It encodes a protein that belongs to the C-type lectin superfamily and is expressed by natural killer (NK) cells. KLRB1 plays a role in the regulation of NK cell function. The protein contains an extracellular domain with motifs characteristic of C-type lectins, a transmembrane domain, and a cytoplasmic domain. It is classified as a type II membrane protein due to its external C terminus. KLRB1 recognizes Lectin Like Transcript-1 (LLT1) as a functional ligand. Binding of LLT1 to KLRB1 leads to clustering of the receptor on the NK cell surface, triggering an inhibitory signal.
KLRB1 plays an inhibitory role in natural killer (NK) cell cytotoxicity. Upon activation, it stimulates specific acid sphingomyelinase (SMPD1), leading to a significant increase in intracellular ceramide levels. Activation also results in the stimulation of AKT1/PKB and RPS6KA1/RSK1 kinases, as well as a marked enhancement of T-cell proliferation induced by anti-CD3. KLRB1 acts as a lectin, binding to the terminal carbohydrate Gal-alpha(1,3)Gal epitope and the N-acetyllactosamine epitope. It also binds to CLEC2D/LLT1 as a ligand, inhibiting NK cell-mediated cytotoxicity and interferon-gamma secretion in target cells.
KLRB1 is also known as CD161, CLEC5B, NKR, NKR-P1, NKR-P1A, NKRP1A, hNKR-P1A.
Associated Diseases
- cancer
- breast cancer
- graft versus host disease
- familial thoracic aortic aneurysm and aortic dissection
- glioblastoma
- aortic aneurysm, familial thoracic 7
- aortic aneurysm, familial thoracic 6
