Expression analysis of new Ly49 genes: most transcripts of Ly49j lack the transmembrane domain.
Five new Ly49 genes, named Ly49j-n, have recently been identified in C57BL/6 mice. This study examined the expression of three of these new genes, Ly49j, k, and n. To determine whether the Ly49j, k, and n genes were transcribed, gene-specific primers were used to amplify cDNA clones for each gene from C57BL/6 interleukin-2-activated natural killer (NK) cell cDNA. A full-length cDNA for Ly49j was detected which encodes a 267 amino acid protein and shares approximately 96% nucleotide identity with Ly49c and i. COS cells transfected with the Ly49j cDNA were shown to react with the monoclonal antibody 8H7, suggesting that the gene likely encodes a functional protein. Many different sized Ly49k and n transcripts were observed, although it is likely that they do not encode functional proteins due to missing exons or severe truncations in the open reading frames. Interestingly, the most abundant Ly49j transcript detected was shown to lack exon 3, which encodes the transmembrane domain. Similar studies performed on the same source of NK cell cDNA using Ly49c- and i-specific primers revealed the presence of transmembrane-less Ly49i transcripts, although at a much lower frequency than observed for Ly49j. We also detected Ly49g and h transcripts lacking the transmembrane domain. Despite the absence of the transmembrane region, the resulting Ly49 transcripts maintain their open reading frames, and therefore could potentially encode cytoplasmic proteins with a role in NK cell function.
McQueen
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KL
Terry Fox Laboratory, B.C. Cancer Agency and the Department of Medical Genetics, University of British Columbia, 601 W10th Avenue, Vancouver, B.C. V5Z 1L3, Canada.
Lohwasser
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S
Takei
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Mager
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D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D000950:Antigens, Ly; D000954:Antigens, Surface / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism; D018076:DNA, Complementary; D015870:Gene Expression; D037102:Lectins / Q000235:genetics; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D055650:NK Cell Lectin-Like Receptor Subfamily A; D020033:Protein Isoforms; D012333:RNA, Messenger; D011971:Receptors, Immunologic / Q000235:genetics*; D055630:Receptors, NK Cell Lectin-Like
D000950:Antigens, Ly; D000954:Antigens, Surface; D018076:DNA, Complementary; C120112:Klra10 protein, mouse; C527091:Klra3 protein, mouse; C527095:Klra7 protein, mouse; D037102:Lectins; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D055650:NK Cell Lectin-Like Receptor Subfamily A; D020033:Protein Isoforms; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D055630:Receptors, NK Cell Lectin-Like