title: Ubiquitin plays an atypical role in GPCR-induced p38 MAP kinase activation on endosomes.
abstract: Protease-activated receptor 1 (PAR1) is a G protein-coupled receptor (GPCR) for thrombin and promotes inflammatory responses through multiple pathways including p38 mitogen-activated protein kinase signaling. The mechanisms that govern PAR1-induced p38 activation remain unclear. Here, we define an atypical ubiquitin-dependent pathway for p38 activation used by PAR1 that regulates endothelial barrier permeability. Activated PAR1 K63-linked ubiquitination is mediated by the NEDD4-2 E3 ubiquitin ligase and initiated recruitment of transforming growth factor-β-activated protein kinase-1 binding protein-2 (TAB2). The ubiquitin-binding domain of TAB2 was essential for recruitment to PAR1-containing endosomes. TAB2 associated with TAB1, which induced p38 activation independent of MKK3 and MKK6. The P2Y1 purinergic GPCR also stimulated p38 activation via NEDD4-2-mediated ubiquitination and TAB1-TAB2. TAB1-TAB2-dependent p38 activation was critical for PAR1-promoted endothelial barrier permeability in vitro, and p38 signaling was required for PAR1-induced vascular leakage in vivo. These studies define an atypical ubiquitin-mediated signaling pathway used by a subset of GPCRs that regulates endosomal p38 signaling and endothelial barrier disruption.
authors.affiliation: Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA, 92093.
authors.forename: Neil J
authors.initials: NJ
authors.lastname: Grimsey
authors.affiliation: Department of Pediatrics, School of Medicine and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093.
authors.forename: Berenice
authors.initials: B
authors.lastname: Aguilar
authors.affiliation: Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA, 92093.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Smith
authors.affiliation: Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA, 92093.
authors.forename: Phillip
authors.initials: P
authors.lastname: Le
authors.affiliation: Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213.
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Soohoo
authors.affiliation: Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213.
authors.forename: Manojkumar A
authors.initials: MA
authors.lastname: Puthenveedu
authors.affiliation: Department of Pediatrics, School of Medicine and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093.
authors.forename: Victor
authors.initials: V
authors.lastname: Nizet
authors.affiliation: Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA, 92093 joanntrejo@ucsd.edu.
authors.forename: JoAnn
authors.initials: J
authors.lastname: Trejo
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002199:Capillary Permeability / Q000502:physiology; D056827:Endosomal Sorting Complexes Required for Transport / Q000235:genetics / Q000378:metabolism; D011992:Endosomes / Q000235:genetics / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D020935:MAP Kinase Signaling System / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D000075702:Nedd4 Ubiquitin Protein Ligases; D044463:Receptor, PAR-1 / Q000235:genetics / Q000378:metabolism*; D025801:Ubiquitin / Q000235:genetics / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism; D054875:Ubiquitination / Q000502:physiology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D056827:Endosomal Sorting Complexes Required for Transport; D044463:Receptor, PAR-1; C486300:TAB1 protein, human; C410585:TAB2 protein, human; C531463:Tab1 protein, mouse; C498761:Tab2 protein, mouse; D025801:Ubiquitin; D000075702:Nedd4 Ubiquitin Protein Ligases; C000618483:Nedd4 protein, human; C000618485:Nedd4L protein, human; C000618461:Nedd4l protein, mouse; D044767:Ubiquitin-Protein Ligases; D048051:p38 Mitogen-Activated Protein Kinases