title: Monocyte chemoattractant protein-1-induced CCR2B receptor desensitization mediated by the G protein-coupled receptor kinase 2.
abstract: Monocyte chemoattractant protein 1 (MCP-1) is a member of the chemokine cytokine family, whose physiological function is mediated by binding to the CCR2 and CCR4 receptors, which are members of the G protein-coupled receptor family. MCP-1 plays a critical role in both activation and migration of leukocytes. Rapid chemokine receptor desensitization is very likely essential for accurate chemotaxis. In this report, we show that MCP-1 binding to the CCR2 receptor in Mono Mac 1 cells promotes the rapid desensitization of MCP-1-induced calcium flux responses. This desensitization correlates with the Ser/Thr phosphorylation of the receptor and with the transient translocation of the G protein-coupled receptor kinase 2 (GRK2, also called beta-adrenergic kinase 1 or betaARK1) to the membrane. We also demonstrate that GRK2 and the uncoupling protein beta-arrestin associate with the receptor, forming a macromolecular complex shortly after MCP-1 binding. Calcium flux responses to MCP-1 in HEK293 cells expressing the CCR2B receptor were also markedly reduced upon cotransfection with GRK2 or the homologous kinase GRK3. Nevertheless, expression of the GRK2 dominant-negative mutant betaARK-K220R did not affect the initial calcium response, but favored receptor response to a subsequent challenge by agonists. The modulation of the CCR2B receptor by GRK2 suggests an important role for this kinase in the regulation of monocyte and lymphocyte response to chemokines.
authors.affiliation: Departamento de Biologia Molecular, Centro de Biologia Molecular "Severo Ochoa,", Universidad Autonoma de Madrid, Campus Cantoblanco, E-28049 Madrid, Spain.
authors.forename: A M
authors.initials: AM
authors.lastname: Aragay
authors.forename: M
authors.initials: M
authors.lastname: Mellado
authors.forename: J M
authors.initials: JM
authors.lastname: Frade
authors.forename: A M
authors.initials: AM
authors.lastname: Martin
authors.forename: M C
authors.initials: MC
authors.lastname: Jimenez-Sainz
authors.forename: C
authors.initials: C
authors.lastname: Martinez-A
authors.forename: F
authors.initials: F
authors.lastname: Mayor
mesh_terms: D019393:Arrestin / Q000378:metabolism; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism; D002451:Cell Compartmentation; D018932:Chemokine CCL2 / Q000494:pharmacology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D054770:G-Protein-Coupled Receptor Kinase 3; D006801:Humans; D009000:Monocytes / Q000187:drug effects*; D010766:Phosphorylation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D054390:Receptors, CCR2; D019707:Receptors, Chemokine; D018121:Receptors, Cytokine / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D051552:beta-Adrenergic Receptor Kinases
chemical_list: D019393:Arrestin; C515334:CCR2 protein, human; D018932:Chemokine CCL2; D054390:Receptors, CCR2; D019707:Receptors, Chemokine; D018121:Receptors, Cytokine; D011994:Recombinant Proteins; D020794:Receptor Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D054770:G-Protein-Coupled Receptor Kinase 3; C517848:GRK3 protein, human; D051552:beta-Adrenergic Receptor Kinases; D002118:Calcium