Killer Cell Lectin Like Receptor Subfamily F, Member 1 (KLRF1)

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. KLRF1 encodes a predicted 231-amino acid type II transmembrane protein that has a 42-amino acid cytoplasmic region containing 2 immunoreceptor tyrosine-based inhibitory motifs (ITIMs); a 23-amino acid transmembrane segment; and a 166-amino acid extracellular region containing a C-type lectin domain with the 6 invariant cys residues observed in all CTLRs. The predominant 1.35-kb transcript was strongly expressed in peripheral blood leukocytes and spleen, with weaker expression in lymph node and adult liver, and no expression detected in bone marrow, thymus, and fetal liver. The KLRF1 gene was not expressed in brain, heart, placenta, lung, kidney, skeletal muscle, and pancreas.