Molecular cloning of KLRI1 and KLRI2, a novel pair of lectin-like natural killer-cell receptors with opposing signalling motifs.
We here report the molecular cloning of a novel family of killer-cell lectin-like (KLR) receptors in the rat and the mouse, termed KLRI. In both species, there are two members, KLRI1 and KLRI2. While the extracellular lectin-like domains of KLRI1 and KLRI2 are similar [74% (rat) and 83% (mouse) amino acid identity], they differ intracellularly. KLRI1 has two immunoreceptor tyrosine-based inhibition motifs (ITIMs) in the cytoplasmic domain, suggesting an inhibitory function. KLRI2 has no ITIM, but a positively charged lysine residue in the transmembrane region, suggesting association with activating adapter molecules. Klri1 and Klri2 are localized within the natural killer (NK) cell gene complex on rat chromosome 4 and mouse chromosome 6. By RT-PCR and Northern blot analysis KLRI1 and KLRI2 were selectively expressed by NK cells in both rat and mouse. Epitope-tagged expression constructs of rat KLRI1 and rat KLRI2 induced surface expression of a nondisulphide-linked protein of M(r) 36,000/39,000 and M(r) 34,000, respectively.
Saether
Per C
PC
Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway. p.c.sather@medisin.uio.no
Westgaard
Ingunn H
IH
Flornes
Line M
LM
Hoelsbrekken
Sigurd E
SE
Ryan
James C
JC
Fossum
Sigbjørn
S
Dissen
Erik
E
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D018076:DNA, Complementary; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism; D037181:Lectins, C-Type / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D010802:Phylogeny; D051381:Rats; D011971:Receptors, Immunologic / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D017422:Sequence Analysis, DNA; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology / Q000502:physiology
D018076:DNA, Complementary; C499791:Klri1 protein, mouse; C499792:Klri1 protein, rat; C499793:Klri2 protein, mouse; C499794:Klri2 protein, rat; D037181:Lectins, C-Type; D011971:Receptors, Immunologic