Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2001-2-22
pubmed:databankReference
pubmed:abstractText
The chemokine signaling system, which coordinates the basal and emergency trafficking of leukocytes, presumably coevolved with the hematopoietic system. To study its phylogenetic origins, we used the open reading frame (ORF) of the human chemokine receptor CXCR4 as a genomic probe, since in mammals it is the most highly conserved chemokine receptor known. CXCR4 cross-hybridized to genomic DNA from mouse and chicken, but not zebrafish, Drosophila, or Caenorhabditis elegans. Accordingly, we cloned the corresponding chicken cDNA. The ORF is 359 codons long versus 352 for human CXCR4, and encodes a protein 82% identical to human CXCR4. In a calcium flux assay of receptor function, CHO-K1 cells stably transfected with the chicken cDNA responded specifically to human SDF-1, the specific ligand for CXCR4, but not to a panel of other chemokines tested at 100 nM. SDF-1 activated the cells in a dose-dependent manner (EC50 approximately 5 nM), whereas parental CHO-K1 cells did not respond. The CHO-K1 cell transfectants also bound 125I-SDF-1 specifically. Leukocytes from chicken peripheral blood expressed chCXCR4 mRNA and responded to human SDF-1 in a calcium flux assay with an EC50 similar to that for chCXCR4-transfected CHO cells, suggesting that this response is mediated by native chCXCR4. Analysis of chicken genomic DNA with the chicken cDNA as probe revealed a pattern consistent with a single copy gene, and the absence of any closely related genes. mRNA was detected in brain, bursa, liver, small and large intestine, embryonal fibroblasts, and blood leukocytes, but not in stomach or pancreas. These results, which identify the first functional non-viral, non-mammalian chemokine receptor, suggest that the origins of a functional chemokine system extend at least to birds and suggest that, as in mammals, CXCR4 functions in many avian tissues.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0741-5400
pubmed:author
pubmed:issnType
Print
pubmed:volume
69
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
297-305
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:11272281-Amino Acid Sequence, pubmed-meshheading:11272281-Animals, pubmed-meshheading:11272281-CHO Cells, pubmed-meshheading:11272281-Chemokine CXCL12, pubmed-meshheading:11272281-Chemokines, CXC, pubmed-meshheading:11272281-Chickens, pubmed-meshheading:11272281-Cloning, Molecular, pubmed-meshheading:11272281-Conserved Sequence, pubmed-meshheading:11272281-Cricetinae, pubmed-meshheading:11272281-Gene Dosage, pubmed-meshheading:11272281-Humans, pubmed-meshheading:11272281-Molecular Sequence Data, pubmed-meshheading:11272281-Organ Specificity, pubmed-meshheading:11272281-Phylogeny, pubmed-meshheading:11272281-RNA, Messenger, pubmed-meshheading:11272281-Receptors, CXCR4, pubmed-meshheading:11272281-Receptors, HIV, pubmed-meshheading:11272281-Sequence Homology, Amino Acid, pubmed-meshheading:11272281-Transfection
pubmed:year
2001
pubmed:articleTitle
Cloning, mRNA distribution, and functional expression of an avian counterpart of the chemokine receptor/HIV coreceptor CXCR4.
pubmed:affiliation
Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
pubmed:publicationType
Journal Article