Molecular Cloning and Functional Expression of a New Human CC-Chemokine Receptor Gene

Abstract

The cloning of several receptors activated by either CC or CXC chemokines and belonging to the G protein-coupled family of receptors has been reported recently. In the present work, we describe the cloning of a human gene, named ChemR13, encoding a new CC-chemokine receptor. The gene encodes a protein of 352 amino acids with a calculated molecular mass of 40 600 Da and displaying a single potential site for N-linked glycosylation. Using a set of overlapping lambda clones, the genomic organisation of the locus was investigated, demonstrating that the ChemR13 gene is physically linked, and in the same orientation, as the CC-CKR2 gene that encodes a receptor for the monocyte chemoattractant protein-1 (MCP-1). A distance of 17.5 kb separates the two coding regions, which share 75% identity in nucleic acid and amino acid sequences. Human ChemR13 was functionally expressed in a stably transfected CHO-K1 cell line. Physiological responses to chemokines were monitored using a microphysiometer. Macrophage inflammatory protein 1 alpha (MIP-1 alpha) was the most potent agonist. MIP-1 beta and RANTES were also active at physiological concentrations. The other CC-chemokines, MCP-1, MCP-2 and MCP-3, as well as CXC-chemokines (IL-8, GRO alpha) had no effect. ChemR13 receptor transcripts were detected by Northern blotting in the promyeloblastic cell line KG-1A, suggesting a potential role in the control of granulocytic lineage proliferation or differentiation. ChemR13 is thus a new member of the growing family of chemokine receptors that mediate the recruitment of cells involved in immune and inflammatory processes. Being the fifth functionally identified receptor in his class, this new CC-chemokine receptor (CC-CKR) is tentatively designated CC-CKR5.

Frequency of polymorphisms of genes coding for HIV-1 co-receptors CCR5 and CCR2 in a Brazilian population

“…PCR primers flanking the 32-nucleotide deletion were 5' CAA AAA GAA GGT CTT CAT TAC ACC 3', and 5' CCT GTG CCT CTT CTT CTC ATT TCG 3', as described previously [5]. The PCR reaction mixture the final 100 µL contained 50 mM MgCl 2 , 10 mM of dNTPs, 20 pmol of each primer, and 0.5 unit of Taq Polymerase in 1X reaction buffer (Gibco BRL, Gaithersburg MD).…”

“…Each of the eight known chemokine receptors is a G protein with a characteristic pattern of ligand binding [3,4]. The receptor CCR5, which also serves as a major coreceptor for macrophage-tropic HIV-1 virus, binds the β-chemokines RANTES (regulated on activation, normal T expressed and secreted), MIP-1α (macrophage inflammatory protein) and MIP-1β [5]. The ligands for CCR2, which also serves as a minor co-receptor for HIV-1 entry, are MCP-1, 2, 3, 4, and 5 (monocyte chemoattractant protein) [6].…”

Pseudopeptide TASP Inhibitors of HIV Entry Bind Specifically to a 95-kDa Cell Surface Protein

“…As the TASP inhibitors were originally designed to mimic the conserved RP dipeptide motif in the V3 loop of HIV-1 and HIV-2 isolates (7), it is plausible then to suggest that such inhibitors manifest their anti-HIV effect by blocking the potential interaction of the V3 loop with p95. It is unlikely that p95 is either Fusin or CC-CKR-5 since these recently described cofactors have molecular masses less than 50 kDa (56,57). Nevertheless, it will be essential to determine the implication of p95 in relation to these cofactors in the HIV envelope-mediated membrane fusion mechanism.…”

Frequency of the CCRdelta32 allele in Brazilians: a study in colorectal cancer and in HTLV-I infection

“…The cc-chemokine receptor-5 gene protein (CCR5) is a seven-transmembrane-domain G protein coupled receptor that has as its natural ligands RANTES (regulated on activation normal T-cell expressed and secreted), MIP-alpha (macrophage inflammatory protein) and MIP-beta, which are members of the CC subfamily of chemokines (Samson et al, 1996a). The CCR5 protein, in concert with CD4, is also the receptor that mediates the internalization of HIV in macrophages and monocytes (Dragic et al, 1996).…”