CC chemokine receptor 5 (CCR5) desensitization: cycling receptors accumulate in the trans-Golgi network.
CC chemokine receptor 5 (CCR5), the major HIV coreceptor, is a G protein-coupled receptor (GPCR) involved in cell activation and migration in response to chemokines. Blockade of CCR5 is an effective anti-HIV strategy, and potent anti-HIV chemokine analogs such as PSC-RANTES have been developed. These inhibitors act by interfering with receptor trafficking, thereby inducing prolonged intracellular sequestration of CCR5. Like many GPCRs, CCR5 is desensitized following agonist activation. The initial steps in this process are well understood, but later stages, including where CCR5 is sequestered during desensitization, and how anti-HIV chemokine analogs intervene to achieve prolonged sequestration, have yet to be elucidated in detail. In this study we demonstrate that CCR5 cycles to and from the cell surface via the endosome recycling compartment and the trans-Golgi network during desensitization, accumulating in the trans-Golgi network following internalization by both PSC-RANTES and CCL5, the native ligand from which it was derived. In addition, we show that unlike CCR5 sequestered by CCL5, CCR5 sequestered by PSC-RANTES cannot be induced to return to the cell surface by addition of the small molecule CCR5 inhibitor, TAK-779, and that association of PSC-RANTES with CCR5 is more durable than that of native CCL5 during desensitization. Our findings reconcile the previously conflicting descriptions of the location of sequestered CCR5 during desensitization, as well as providing more general insights into potential trafficking routes for endocytosed GPCRs and further elucidation of the unusual inhibitory mechanism of chemokine analogs with potent anti-HIV activity.
Department of Structural Biology and Bioinformatics, Faculty of Medicine, University of Geneva, 1211 Geneva 4, Switzerland.
Jean-Michel
JM
Escola
Gabriel
G
Kuenzi
Hubert
H
Gaertner
Michelangelo
M
Foti
Oliver
O
Hartley
D000577:Amides / Q000494:pharmacology; D000818:Animals; D019380:Anti-HIV Agents / Q000494:pharmacology; D016466:CHO Cells; D002462:Cell Membrane / Q000378:metabolism* / Q000821:virology; D006224:Cricetinae; D003412:Cricetulus; D011992:Endosomes / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D007700:Kinetics; D007963:Leukocytes, Mononuclear / Q000166:cytology; D008024:Ligands; D018613:Microscopy, Confocal / Q000379:methods; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D019713:Receptors, CCR5 / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism / Q000821:virology; D021601:trans-Golgi Network / Q000378:metabolism*
D000577:Amides; D019380:Anti-HIV Agents; D008024:Ligands; D000644:Quaternary Ammonium Compounds; D019713:Receptors, CCR5; D043562:Receptors, G-Protein-Coupled; C119369:TAK 779