Agonist-induced trafficking of the low-affinity formyl peptide receptor FPRL1.
The formyl peptide-like receptor FPRL1 is a member of the chemoattractant subfamily of G protein- coupled receptors involved in regulating leukocyte migration in inflammation. To elucidate mechanisms underlying the internalization of ligand-bound FPRL1 and possible receptor recycling, we characterized the endocytic itinerary of FPRL1. We show that agonist-triggered internalization from the plasma membrane into intracellular compartments is prevented by perturbation of clathrin-mediated endocytosis, such as expression of the dominant-negative clathrin Hub mutant, siRNA-mediated depletion of cellular clathrin and expression of a dominant-negative mutant of the large GTPase dynamin. Internalized FPRL1 co-localized with endocytosed transferrin and the small GTPases Rab4 and Rab11 in vesicular structures most resembling recycling endosomes. Recycling of FPRL1 was significantly reduced by pretreatment with PI3-kinase inhibitors. Thus, ligand-bound FPRL1 undergoes primarily clathrin-mediated and dynamin-dependent endocytosis and the receptor recycles via a rapid PI3-kinase-sensitive route as well as pathways involving perinuclear recycling endosomes.
Ernst
S
S
Center for Molecular Biology of Inflammation, Institute for Medical Biochemistry, von Esmarch-Str. 56, 48149 Münster, Germany.
Zobiack
N
N
Boecker
K
K
Gerke
V
V
Rescher
U
U
D002867:Chromones / Q000494:pharmacology; D002966:Clathrin / Q000037:antagonists & inhibitors / Q000378:metabolism; D034281:Dynamins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D004705:Endocytosis / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic; D006367:HeLa Cells; D006801:Humans; D008024:Ligands; D008856:Microscopy, Fluorescence; D009025:Morpholines / Q000494:pharmacology; D009842:Oligopeptides / Q000494:pharmacology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D021381:Protein Transport / Q000187:drug effects; D044042:Receptors, Formyl Peptide / Q000819:agonists* / Q000235:genetics / Q000378:metabolism*; D044067:Receptors, Lipoxin / Q000819:agonists* / Q000235:genetics / Q000378:metabolism*
D002867:Chromones; D002966:Clathrin; D034281:Dynamins; D008024:Ligands; D009025:Morpholines; D009842:Oligopeptides; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D044042:Receptors, Formyl Peptide; D044067:Receptors, Lipoxin; C105101:FPR2 protein, human; C113617:Trp-Lys-Tyr-Met-Val-Met; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one