title: Genes encoding putative natural killer cell C-type lectin receptors in teleostean fishes.
abstract: Mammalian natural killer (NK) cells are cytotoxic lymphocytes that express receptors specific for MHC class I molecules. The NK cell receptors belong to two structurally unrelated families, the killer cell Ig-like receptors and the killer cell C-type lectin receptors. We describe a cDNA clone derived from the bony (cichlid) fish Paralabidochromis chilotes and show that it encodes a protein related to the CD94/NK cell group 2 (NKG2) subfamily of the killer cell C-type lectin receptors. The gene encoding this receptor in a related species, Oreochromis niloticus, has a similar structure to the human CD94/NKG2 genes and is a member of a multigene cluster that resembles the mammalian NK cell gene complex. Thus, the CD94/NKG2 subfamily of NK cell receptors must have arisen before the divergence of fish and tetrapods and may have retained its function (possibly monitoring the expression of MHC class I molecules) for >400 million years.
authors.affiliation: Max-Planck-Institut für Biologie, Abteilung Immungenetik and Abteilung Membranbiochemie, Corrensstrasse 42, D-72076 Tübingen, Germany. akie.sato@tuebingen.mpg.de
authors.forename: Akie
authors.initials: A
authors.lastname: Sato
authors.forename: Werner E
authors.initials: WE
authors.lastname: Mayer
authors.forename: Peter
authors.initials: P
authors.lastname: Overath
authors.forename: Jan
authors.initials: J
authors.lastname: Klein
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis; D001483:Base Sequence; D015139:Blotting, Southern; D022202:Chromosomes, Artificial, Bacterial; D023681:Cichlids; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism; D005091:Exons; D015723:Gene Library; D006801:Humans; D007438:Introns; D007694:Killer Cells, Natural / Q000378:metabolism*; D037181:Lectins, C-Type / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D007962:Leukocytes / Q000378:metabolism; D008024:Ligands; D008969:Molecular Sequence Data; D051920:NK Cell Lectin-Like Receptor Subfamily D; D010802:Phylogeny; D012313:RNA / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
chemical_list: D015703:Antigens, CD; D018076:DNA, Complementary; C497869:KLRD1 protein, human; D037181:Lectins, C-Type; D008024:Ligands; D051920:NK Cell Lectin-Like Receptor Subfamily D; D012313:RNA