Characterization and expression of an Fc gamma receptor cDNA cloned from rat natural killer cells.
A cDNA clone for an IgG-binding Fc receptor, rtFc gamma R alpha, of the rat natural killer cell line CRNK-16 is characterized here. This clone encodes an Fc gamma receptor as shown by the ability of cDNA-transfected COS cells to rosette IgG-coated sheep erythrocytes. The rtFc gamma R alpha is exceptionally homologous to the mouse moFc gamma R alpha, with 77% protein sequence identity and 71% nucleic acid identity overall. The transmembrane region of the rtFc gamma R alpha contains the sequence Leu-Phe-Ala-Val-Asp-Thr-Gly-Leu, which is present in the membrane sequences of four other Fc receptors including mouse Fc gamma R alpha, human Fc gamma RIII-2, and the Fc epsilon R alpha subunits of the rat and human high-affinity IgE-binding receptors. Also, the rtFc gamma R alpha cytoplasmic domain exhibits specific homology to other receptors derived from natural killer cells, human Fc gamma RIII-2 and mouse Fc gamma R alpha. However, the rtFc gamma R alpha cDNA clone is complementary to at least two different-sized mRNAs expressed by CRNK-16 cells, contrasting the single Fc gamma R-related mRNA species expressed by human and mouse natural killer cells. These rat mRNAs are homologous to both the 5' and the 3' end of the cDNA clone, suggesting that they may be (i) splice variants of one transcript or (ii) products of different but highly related genes.
Department of Biological Sciences, University of California, Santa Barbara 93106.
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Zeger
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Hogarth
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Sears
D000595:Amino Acid Sequence; D000818:Animals; D000943:Antigens, Differentiation / Q000235:genetics*; D001483:Base Sequence; D015152:Blotting, Northern; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D015723:Gene Library; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology*; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D011061:Poly A / Q000235:genetics / Q000302:isolation & purification; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger; D051381:Rats; D011961:Receptors, Fc / Q000235:genetics*; D017452:Receptors, IgG; D015183:Restriction Mapping; D012397:Rosette Formation; D012689:Sequence Homology, Nucleic Acid; D014162:Transfection
D000943:Antigens, Differentiation; D007074:Immunoglobulin G; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D011961:Receptors, Fc; D017452:Receptors, IgG; D011061:Poly A; D012313:RNA; D004247:DNA