title: Divergent β-arrestin-dependent signaling events are dependent upon sequences within G-protein-coupled receptor C termini.
abstract: β-Arrestins are multifunctional adaptor proteins that, upon recruitment to an activated G-protein-coupled receptor, can promote desensitization of G-protein signaling and receptor internalization while simultaneously eliciting an independent signal. The result of β-arrestin signaling depends upon the activating receptor. For example, activation of two Gα(q)-coupled receptors, protease-activated receptor-2 (PAR(2)) and neurokinin-1 receptor (NK1R), results in drastically different signaling events. PAR(2) promotes β-arrestin-dependent membrane-sequestered extracellular signal-regulated kinase (ERK1/2) activation, cofilin activation, and cell migration, whereas NK1R promotes nuclear ERK1/2 activation and proliferation. Using bioluminescence resonance energy transfer to monitor receptor/β-arrestin interactions in real time, we observe that PAR(2) has a higher apparent affinity for both β-arrestins than does NK1R, recruits them at a faster rate, and exhibits more rapid desensitization of the G-protein signal. Furthermore, recruitment of β-arrestins to PAR(2) does not require prior Gα(q) signaling events, whereas inhibition of Gα(q) signaling intermediates inhibits recruitment of β-arrestins to NK1R. Using chimeric receptors in which the C terminus of PAR(2) is fused to the N terminus of NK1R and vice versa and a critical Ser/Thr mutant of PAR(2), we demonstrate that interactions between β-arrestins and specific phosphoresidues in the C termini of each receptor are crucial for determining the rate and magnitude of β-arrestin recruitment as well as the ultimate signaling outcome.
authors.affiliation: Cell Molecular Developmental Biology Program, University of California, Riverside, California 92521, USA.
authors.forename: Kasturi
authors.initials: K
authors.lastname: Pal
authors.forename: Maneesh
authors.initials: M
authors.lastname: Mathur
authors.forename: Puneet
authors.initials: P
authors.lastname: Kumar
authors.forename: Kathryn
authors.initials: K
authors.lastname: DeFea
mesh_terms: D051339:Actin Depolymerizing Factors / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D019390:Arrestins / Q000378:metabolism*; D016466:CHO Cells; D002118:Calcium / Q000378:metabolism; D002465:Cell Movement; D006224:Cricetinae; D004705:Endocytosis; D004789:Enzyme Activation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D007700:Kinetics; D051379:Mice; D050505:Mutant Proteins / Q000378:metabolism; D064729:Neurokinin-1 Receptor Antagonists; D010766:Phosphorylation; D044464:Receptor, PAR-2 / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism*; D018040:Receptors, Neurokinin-1 / Q000737:chemistry* / Q000378:metabolism*; D015398:Signal Transduction; D013329:Structure-Activity Relationship; D013347:Subcellular Fractions / Q000378:metabolism; D000071557:beta-Arrestins
chemical_list: D051339:Actin Depolymerizing Factors; D019390:Arrestins; D050505:Mutant Proteins; D064729:Neurokinin-1 Receptor Antagonists; D044464:Receptor, PAR-2; D018040:Receptors, Neurokinin-1; D000071557:beta-Arrestins; D048049:Extracellular Signal-Regulated MAP Kinases; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D002118:Calcium