title: Microtubule-Associated Protein EB3 Regulates IP3 Receptor Clustering and Ca(2+) Signaling in Endothelial Cells.
abstract: The mechanisms by which the microtubule cytoskeleton regulates the permeability of endothelial barrier are not well understood. Here, we demonstrate that microtubule-associated end-binding protein 3 (EB3), a core component of the microtubule plus-end protein complex, binds to inositol 1,4,5-trisphosphate receptors (IP3Rs) through an S/TxIP EB-binding motif. In endothelial cells, α-thrombin, a pro-inflammatory mediator that stimulates phospholipase Cβ, increases the cytosolic Ca(2+) concentration and elicits clustering of IP3R3s. These responses, and the resulting Ca(2+)-dependent phosphorylation of myosin light chain, are prevented by depletion of either EB3 or mutation of the TxIP motif of IP3R3 responsible for mediating its binding to EB3. We also show that selective EB3 gene deletion in endothelial cells of mice abrogates α-thrombin-induced increase in endothelial permeability. We conclude that the EB3-mediated interaction of IP3Rs with microtubules controls the assembly of IP3Rs into effective Ca(2+) signaling clusters, which thereby regulate microtubule-dependent endothelial permeability.
authors.affiliation: Department of Pharmacology and The Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA.
authors.forename: Melissa
authors.initials: M
authors.lastname: Geyer
authors.affiliation: Department of Pharmacology and The Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA.
authors.forename: Fei
authors.initials: F
authors.lastname: Huang
authors.affiliation: Department of Pharmacology and The Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Pharmacology and The Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Vogel
authors.affiliation: Department of Pharmacology and The Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA.
authors.forename: Asrar B
authors.initials: AB
authors.lastname: Malik
authors.affiliation: Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK.
authors.forename: Colin W
authors.initials: CW
authors.lastname: Taylor
authors.affiliation: Department of Pharmacology and The Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA. Electronic address: ykomarov@uic.edu.
authors.forename: Yulia A
authors.initials: YA
authors.lastname: Komarova
mesh_terms: D000818:Animals; D016466:CHO Cells; D020013:Calcium Signaling; D002199:Capillary Permeability; D006224:Cricetinae; D003412:Cricetulus; D042783:Endothelial Cells / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000378:metabolism*; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding
chemical_list: C522423:EB3 protein, mouse; D053496:Inositol 1,4,5-Trisphosphate Receptors; D008869:Microtubule-Associated Proteins