Functional coupling of NKR-P1 receptors to various heterotrimeric G proteins in rat interleukin-2-activated natural killer cells.
NKR-P1 molecules constitute a family of type II membrane receptors in natural killer (NK) cells that preferentially activate NK cell killing and release of interferon-gamma from these cells. Here, we demonstrate that anti-NKR-P1 enhances GTP binding in rat interleukin-2-activated NK cell membranes; GTP binding to Gi3alpha, Gsalpha, Gq,11alpha, and Gzalpha increased noticeably in these cell membranes after treatment with anti-NKR-P1. Western blot analysis of membrane proteins prepared from interleukin-2-activated NK cells reveals the presence of Gi1,2alpha, Gi3alpha, Goalpha, Gsalpha, Gq, 11alpha, Gzalpha, and G12alpha, but not G13alpha. However, only alphai3, alphas, alphaq,11, and alphaz, but not alphai1,2, alphao, alpha12, or alpha13 subunits when immunoprecipitated with the appropriate anti-G protein antibodies, are associated with NKR-P1 when immunoblotted with anti-NKR-P1. Reciprocally, NKR-P1 immunoprecipitated with anti-NKR-P1 is associated with alphai3, alphas, alphaq,11, and alphaz immunoblotted with anti-G proteins. These results are the first to demonstrate the physical and functional coupling of NKR-P1 to the heterotrimeric G proteins in NK cells.
Al-Aoukaty
A
A
Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo, N-0317 Oslo, Norway. ala.aoukaty@basalmed.uio.no
Rolstad
B
B
Maghazachi
A A
AA
D000818:Animals; D000954:Antigens, Surface / Q000378:metabolism*; D002478:Cells, Cultured; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism; D007376:Interleukin-2 / Q000494:pharmacology*; D007694:Killer Cells, Natural / Q000187:drug effects / Q000378:metabolism*; D037181:Lectins, C-Type; D008213:Lymphocyte Activation / Q000187:drug effects; D008562:Membrane Glycoproteins / Q000378:metabolism*; D055651:NK Cell Lectin-Like Receptor Subfamily B; D011485:Protein Binding; D051381:Rats; D015398:Signal Transduction
D000954:Antigens, Surface; D007376:Interleukin-2; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D055651:NK Cell Lectin-Like Receptor Subfamily B; D006160:Guanosine Triphosphate; D019204:GTP-Binding Proteins