A homolog of the human chemokine receptor CXCR1 is expressed in the mouse.
Two distinct genes are present in the human genome encoding receptors for human interleukin-8 (hCXCL8), referred to as hCXCR1 and hCXCR2. While it seems clear that orthologous genes are present in the genomes of several mammals, the existence of a gene encoding an ortholog of hCXCR1 in the mouse has thus far been controversial. We have isolated a cDNA that is highly similar to the cDNAs of hCXCR1 and hCXCR2, but is clearly distinct from the cDNA encoding mouse CXCR2 (mCXCR2). The encoded protein, designated mouse CXCR1-like (mCXCR1-like), shares 64, 57, 57, and 89% identical amino acids with hCXCR1, hCXCR2, mCXCR2, and rCXCR1-like, respectively. The gene encoding mCXCR1-like was mapped to mouse chromosome 1 and its genomic organization was determined to be very similar to the organization of the gene encoding hCXCR1. Like hCXCR1, mCXCR1-like was found to be expressed at the mRNA level in neutrophils. In addition, mRNA encoding mCXCR1-like was detected in liver, kidney, and spleen. In spleen, mCXCR1-like transcripts were predominantly found in CD4+ T cells. In liver, mCXCR1-like transcripts were identified in residual CD3+ T cells and macrophages, suggesting that mCXCR1-like may regulate inflammatory and immunological processes in the liver. When expressed as a recombinant protein, mCXCR1-like was not activated by a large panel of known CXC chemokines of human and murine origin. These findings suggest that a homolog or ortholog of hCXCR1 is expressed in the mouse to be activated by a hitherto unknown CXC chemokine of the mouse.
Moepps
Barbara
B
Department of Pharmacology and Toxicology, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
Nuesseler
Elke
E
Braun
Mike
M
Gierschik
Peter
P
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology; D002874:Chromosome Mapping; D002875:Chromosomes / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D019281:Dimerization; D051960:GTP-Binding Protein alpha Subunit, Gi2 / Q000737:chemistry / Q000235:genetics; D006801:Humans; D007668:Kidney / Q000737:chemistry / Q000378:metabolism; D008099:Liver / Q000737:chemistry / Q000378:metabolism; D008214:Lymphocytes / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D023062:Receptors, Interleukin-8A / Q000032:analysis / Q000737:chemistry* / Q000235:genetics*; D023063:Receptors, Interleukin-8B / Q000737:chemistry / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D016415:Sequence Alignment; D013154:Spleen / Q000737:chemistry / Q000378:metabolism; D014018:Tissue Distribution
D000906:Antibodies; D018076:DNA, Complementary; D051960:GTP-Binding Protein alpha Subunit, Gi2; D023062:Receptors, Interleukin-8A; D023063:Receptors, Interleukin-8B; D011994:Recombinant Proteins; C508968:Cxcr1 protein, mouse