Characterization of complementary DNA clones encoding the rabbit IL-8 receptor.
IL-8 is a proinflammatory cytokine that functions as a chemoattractant for neutrophils. Recently, cDNA clones encoding the human neutrophil IL-8R were isolated by an expression cloning strategy. The amino acid sequence of the human IL-8R was sufficiently similar to a published sequence for an isoform of the rabbit FMLP receptor that we considered the possibility that the rabbit sequence might bind IL-8 as well. In order to establish its ligand specificity, we have isolated and characterized cDNA clones encoding the rabbit receptor. These cDNA clones, when expressed in mammalian cells, confer high affinity IL-8 binding (Kd = 3.6 nM), lack detectable binding of FMLP, and produce a transient increase in the intracellular Ca2+ concentration in response to IL-8 but not to FMLP. These data demonstrate that the reported rabbit FMLP receptor is the rabbit IL-8R, not an isoform of the FMLP receptor. In addition, the amino acid sequence of the rabbit IL-8R encoded by these cDNA clones differs at 23 amino acids (of 355) from that previously published.
Lee
J
J
Department of Molecular Biology Genetech, Inc., South San Francisco, CA 94080.
Kuang
W J
WJ
Rice
G C
GC
Wood
W I
WI
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000737:chemistry* / Q000302:isolation & purification; D016209:Interleukin-8 / Q000378:metabolism*; D008969:Molecular Sequence Data; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000378:metabolism; D011817:Rabbits; D044042:Receptors, Formyl Peptide; D011971:Receptors, Immunologic / Q000032:analysis / Q000235:genetics*; D023062:Receptors, Interleukin-8A
D016209:Interleukin-8; D044042:Receptors, Formyl Peptide; D011971:Receptors, Immunologic; D023062:Receptors, Interleukin-8A; D009240:N-Formylmethionine Leucyl-Phenylalanine; D004247:DNA