MOLECULAR-CLONING AND CHROMOSOMAL MAPPING OF A NOVEL HUMAN GENE, CHEMR1, EXPRESSED IN T-LYMPHOCYTES AND POLYMORPHONUCLEAR CELLS AND ENCODING A PUTATIVE CHEMOKINE RECEPTOR

We describe the cloning of a human gene, named ChemR1, encoding a new putative chemokine receptor sharing 48% identity with CC-chemokine rec eptor (CCR)4 and 44% identity with CCR1. It displays four extracellula r cysteines that are conserved among all other chemokine receptors. Ch emR1 transcripts were detected by Northern blotting in the T lymphobla stic cell lines Jurkat and MOLT-4, but not in the pre-B lymphoblastic cell line JM-1. ChemR1 receptor transcripts were also detected by reve rse transcription and polymerase chain reaction analysis in unstimulat ed CD4(+) and CD8(+) T cells and polymorphonuclear cells prepared from peripheral blood. The chromosomal localization was performed by radia tion hybrid mapping and testing of a panel of yeast artificial chromos ome clones. This allowed the assignment of the ChemR1 receptor gene to the p21.3-24 region of human chromosome 3, in close proximity with th e functionally characterized CCR. Future work is required to identify the ligand(s) of this new chemokine receptor and to define its role in the recruitment of white blood cell populations.