title: Pyk2 phosphorylation of VE-PTP downstream of STIM1-induced Ca2+entry regulates disassembly of adherens junctions.
abstract: Vascular endothelial protein tyrosine phosphatase (VE-PTP) stabilizes endothelial adherens junctions (AJs) through constitutive dephosphorylation of VE-cadherin. Here we investigated the role of stromal interaction molecule 1 (STIM1) activation of store-operated Ca2+entry (SOCE) in regulating AJ assembly. We observed that SOCE induced by STIM1 activated Pyk2 in human lung microvascular endothelial cells (ECs) and induced tyrosine phosphorylation of VE-PTP at Y1981. Pyk2-induced tyrosine phosphorylation of VE-PTP promotedSrcbinding to VE-PTP,Srcactivation, and subsequent VE-cadherin phosphorylation and thereby increased the endothelial permeability response. The increase in permeability was secondary to disassembly of AJs. Pyk2-mediated responses were blocked in EC-restrictedStim1knockout mice, indicating the requirement for STIM1 in initiating the signaling cascade. A peptide derived from the Pyk2 phosphorylation site on VE-PTP abolished the STIM1/SOCE-activated permeability response. Thus Pyk2 activation secondary to STIM1-induced SOCE causes tyrosine phosphorylation of VE-PTP, and VE-PTP, in turn, binds to and activatesSrc, thereby phosphorylating VE-cadherin to increase endothelial permeability through disassembly of AJs. Our results thus identify a novel signaling mechanism by which STIM1-induced Ca2+signaling activates Pyk2 to inhibit the interaction of VE-PTP and VE-cadherin and hence increase endothelial permeability. Therefore, targeting the Pyk2 activation pathway may be a potentially important anti-inflammatory strategy.
authors.affiliation: Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois.
authors.forename: Dheeraj
authors.initials: D
authors.lastname: Soni
authors.affiliation: Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois.
authors.forename: Sushil C
authors.initials: SC
authors.lastname: Regmi
authors.affiliation: Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois.
authors.forename: Dong-Mei
authors.initials: DM
authors.lastname: Wang
authors.affiliation: Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois.
authors.forename: Auditi
authors.initials: A
authors.lastname: DebRoy
authors.affiliation: Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois.
authors.forename: You-Yang
authors.initials: YY
authors.lastname: Zhao
authors.affiliation: Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Vogel
authors.affiliation: Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois.
authors.forename: Asrar B
authors.initials: AB
authors.lastname: Malik
authors.affiliation: Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois tiruc@uic.edu.
authors.forename: Chinnaswamy
authors.initials: C
authors.lastname: Tiruppathi
mesh_terms: D022005:Adherens Junctions / Q000378:metabolism*; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D015820:Cadherins / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002199:Capillary Permeability; D002463:Cell Membrane Permeability; D042783:Endothelial Cells / Q000378:metabolism; D004789:Enzyme Activation; D051418:Focal Adhesion Kinase 2 / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D020868:Gene Silencing; D006801:Humans; D008810:Mice, Inbred C57BL; D055806:Microvessels / Q000166:cytology; D008954:Models, Biological; D009363:Neoplasm Proteins / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D044463:Receptor, PAR-1 / Q000378:metabolism; D054631:Receptor-Like Protein Tyrosine Phosphatases, Class 3 / Q000378:metabolism*; D000071737:Stromal Interaction Molecule 1 / Q000378:metabolism*; D019061:src-Family Kinases / Q000378:metabolism; D000099152:Cadherin 5
chemical_list: D015703:Antigens, CD; D015820:Cadherins; D002118:Calcium; D051418:Focal Adhesion Kinase 2; D009363:Neoplasm Proteins; D010455:Peptides; D019000:Phosphotyrosine; D044463:Receptor, PAR-1; D054631:Receptor-Like Protein Tyrosine Phosphatases, Class 3; D000071737:Stromal Interaction Molecule 1; D019061:src-Family Kinases; D000099152:Cadherin 5; C103530:STIM1 protein, human; C100757:Stim1 protein, mouse
keywords: Pyk2; VE-cadherin; permeability increase; store-operated Ca2+ entry; stromal interaction molecule 1; thrombin; vascular endothelial protein tyrosine phosphatase