title: Protease activated receptor-1 mediated dual kinase receptor transactivation stimulates the expression of glycosaminoglycan synthesizing genes.
abstract: G protein-coupled receptors (GPCR) are one of the most important targets for therapeutics due to their abundance and diversity. The G protein-coupled receptor for thrombin can transactivate protein tyrosine kinase receptors (PTKR) and we have recently established that it can also transactivate serine/threonine kinase receptors (S/TKR). A comprehensive knowledge of the signalling pathways that GPCR transactivation elicits is necessary to fully understand the implications of both GPCR activation and the impact of target drugs. Here, we demonstrate that thrombin elicits dual transactivation-dependent signalling pathways to stimulate mRNA expression of glycosaminoglycan synthesizing enzymes chondroitin 4-O-sulfotransferase 1 and chondroitin sulfate synthase 1. The PTKR mediated response involves matrix metalloproteinases and the phosphorylation of the MAP kinase Erk. The S/TKR mediated response differs markedly and involves the phosphorylation of Smad2 carboxy terminal serine residues and does not involve matrix metalloproteinases. This work shows that all of the thrombin mediated signalling to glycosaminoglycan synthesizing enzyme gene expression occurs via transactivation-dependent pathways and does not involve transactivation-independent signalling. These findings highlight the complexity of thrombin-mediated transactivation signalling and the broader implications of GPCR targeted therapeutics.
authors.affiliation: Discipline of Pharmacy, School of Medical Sciences and Diabetes Complications Group, Health Innovations Research Institute, RMIT University, Bundoora, VIC 3083, Australia. Electronic address: Danielle.kamato@rmit.edu.au.
authors.forename: Danielle
authors.initials: D
authors.lastname: Kamato
authors.affiliation: School of Pharmacy, The University of Queensland, Wooloongabba, QLD 4102, Australia. Electronic address: l.thach@uq.edu.au.
authors.forename: Lyna
authors.initials: L
authors.lastname: Thach
authors.affiliation: Discipline of Pharmacy, School of Medical Sciences and Diabetes Complications Group, Health Innovations Research Institute, RMIT University, Bundoora, VIC 3083, Australia. Electronic address: robel.getachew@rmit.edu.au.
authors.forename: Robel
authors.initials: R
authors.lastname: Getachew
authors.affiliation: The Brigham and Harvard Medical School, Boston, MA 02115, USA. Electronic address: micah.burch66@gmail.com.
authors.forename: Micah
authors.initials: M
authors.lastname: Burch
authors.affiliation: Department of Physiology & Pharmacology, University of Calgary, Calgary, Alberta, Canada; Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada. Electronic address: mhollenb@ucalgary.ca.
authors.forename: Morley D
authors.initials: MD
authors.lastname: Hollenberg
authors.affiliation: Faculty of Health Sciences, University of Macau, Taipa, Macau, China; Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510006, China. Electronic address: whzheng1233@163.com.
authors.forename: Wenhua
authors.initials: W
authors.lastname: Zheng
authors.affiliation: Discipline of Pharmacy, School of Medical Sciences and Diabetes Complications Group, Health Innovations Research Institute, RMIT University, Bundoora, VIC 3083, Australia; School of Pharmacy, The University of Queensland, Wooloongabba, QLD 4102, Australia. Electronic address: p.little@uq.edu.au.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Little
authors.affiliation: Discipline of Pharmacy, School of Medical Sciences and Diabetes Complications Group, Health Innovations Research Institute, RMIT University, Bundoora, VIC 3083, Australia. Electronic address: narin.osman@rmit.edu.au.
authors.forename: Narin
authors.initials: N
authors.lastname: Osman
mesh_terms: D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D006025:Glycosaminoglycans / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D044463:Receptor, PAR-1 / Q000378:metabolism*; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*; D051899:Smad2 Protein / Q000378:metabolism; D015533:Transcriptional Activation / Q000502:physiology*
chemical_list: D006025:Glycosaminoglycans; D044463:Receptor, PAR-1; D018125:Receptors, Transforming Growth Factor beta; C497782:SMAD2 protein, human; D051899:Smad2 Protein; D017346:Protein Serine-Threonine Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I
keywords: Glycosaminoglycan enzymes; Smad linker region; Thrombin; Transactivation-dependent; Transforming growth factor β