title: MAFA-L, an ITIM-containing receptor encoded by the human NK cell gene complex and expressed by basophils and NK cells.
abstract: The natural killer cell gene complex on human chromosome 12p12-13 encodes several C-type lectin receptor genes expressed by NK cells and other hematopoietic cells. We have identified a novel receptor gene in this region encoding a putative type II transmembrane glycoprotein. The product is 54% identical to the rat mast cell function-associated antigen (MAFA), which inhibits mast cell activation by IgE. The human MAFA-like receptor (MAFA-L) and the rat MAFA protein are expressed by basophils and both have an immunoreceptor tyrosine-based inhibitory motif in the cytoplasmic tail, consistent with an inhibitory role in basophil activation. Unlike rat MAFA, expression of the MAFA-L gene is not limited to mast cells and basophils. In common with other genes in the NK cell gene complex MAFA-L is also expressed by natural killer cells as well as the monocyte-like cell-line U937. Expression in NK cells is restricted to peripheral blood NK cells, decidual NK cells do not express MAFA-L. While MAFA-L and rat MAFA might have a similar role in basophils, the expression of MAFA-L in other cell types implies additional functions for this molecule. The presence of the MAFA-L gene in the human NK cell complex indicates that this locus encodes C-type lectin receptors expressed by a variety of cells important in host defense.
authors.affiliation: HGMP Resource Centre, Wellcome Genome Campus, Hinxton, GB.
authors.forename: S
authors.initials: S
authors.lastname: Butcher
authors.forename: K L
authors.initials: KL
authors.lastname: Arney
authors.forename: G P
authors.initials: GP
authors.lastname: Cook
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001491:Basophils / Q000737:chemistry*; D002874:Chromosome Mapping; D002881:Chromosomes, Human, Pair 12; D006801:Humans; D007694:Killer Cells, Natural / Q000737:chemistry*; D037102:Lectins / Q000032:analysis* / Q000235:genetics; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins / Q000032:analysis* / Q000235:genetics; D008969:Molecular Sequence Data; D051381:Rats; D011971:Receptors, Immunologic; D015534:Trans-Activators
chemical_list: C113413:KLRG1 protein, human; C094696:Klrg1 protein, rat; D037102:Lectins; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; D015534:Trans-Activators