NKp44, a triggering receptor involved in tumor cell lysis by activated human natural killer cells, is a novel member of the immunoglobulin superfamily.
Surface receptors involved in natural killer (NK) cell triggering during the process of tumor cell lysis have recently been identified. Of these receptors, NKp44 is selectively expressed by IL-2- activated NK cells and may contribute to the increased efficiency of activated NK cells to mediate tumor cell lysis. Here we describe the molecular cloning of NKp44. Analysis of the cloned cDNA indicated that NKp44 is a novel transmembrane glycoprotein belonging to the Immunoglobulin superfamily characterized by a single extracellular V-type domain. The charged amino acid lysine in the transmembrane region may be involved in the association of NKp44 with the signal transducing molecule killer activating receptor-associated polypeptide (KARAP)/DAP12. These molecules were found to be crucial for the surface expression of NKp44. In agreement with data of NKp44 surface expression, the NKp44 transcripts were strictly confined to activated NK cells and to a minor subset of TCR-gamma/delta+ T lymphocytes. Unlike genes coding for other receptors involved in NK cell triggering or inhibition, the NKp44 gene is on human chromosome 6.
Istituto Nazionale per la Ricerca sul Cancro and Centro Biotecnologie Avanzate, 16132 Genova, Italy.
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Cantoni
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Bottino
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Vitale
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Pessino
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Augugliaro
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Malaspina
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Parolini
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Moretta
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Moretta
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Biassoni
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002451:Cell Compartmentation; D002896:Chromosomes, Human, Pair 6; D003001:Cloning, Molecular; D017124:Conserved Sequence; D003602:Cytotoxicity, Immunologic; D018076:DNA, Complementary / Q000235:genetics; D006801:Humans; D007136:Immunoglobulins / Q000145:classification / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D007694:Killer Cells, Natural / Q000276:immunology*; D016131:Lymphocyte Subsets / Q000276:immunology; D008565:Membrane Proteins; D051379:Mice; D008969:Molecular Sequence Data; D055629:Natural Cytotoxicity Triggering Receptor 2; D011485:Protein Binding; D012333:RNA, Messenger / Q000302:isolation & purification; D011971:Receptors, Immunologic / Q000145:classification / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013045:Species Specificity
D048868:Adaptor Proteins, Signal Transducing; D018076:DNA, Complementary; D007136:Immunoglobulins; D008565:Membrane Proteins; C112837:NCR2 protein, human; D055629:Natural Cytotoxicity Triggering Receptor 2; D012333:RNA, Messenger; D011971:Receptors, Immunologic; C110546:TYROBP protein, human