title: STIM1 Phosphorylation at Y361 Recruits Orai1 to STIM1 Puncta and Induces Ca2+Entry.
abstract: Store-operated Ca2+entry (SOCE) mediates the increase in intracellular calcium (Ca2+) in endothelial cells (ECs) that regulates several EC functions including tissue-fluid homeostasis. Stromal-interaction molecule 1 (STIM1), upon sensing the depletion of (Ca2+) from the endoplasmic reticulum (ER) store, organizes as puncta that trigger store-operated Ca2+entry (SOCE) via plasmalemmal Ca2+-selective Orai1 channels. While the STIM1 and Orai1 binding interfaces have been mapped, signaling mechanisms activating STIM1 recruitment of Orai1 and STIM1-Orai1 interaction remains enigmatic. Here, we show that ER Ca2+-store depletion rapidly induces STIM1 phosphorylation at Y361 via proline-rich kinase 2 (Pyk2) in ECs. Surprisingly, the phospho-defective STIM1-Y361F mutant formed puncta but failed to recruit Orai1, thereby preventing. SOCE Furthermore, studies in mouse lungs, expression of phosphodefective STIM1-Y361F mutant in ECs prevented the increase in vascular permeability induced by the thrombin receptor, protease activated receptor 1 (PAR1). Hence, Pyk2-dependent phosphorylation of STIM1 at Y361 is a critical phospho-switch enabling recruitment of Orai1 into STIM1 puncta leading to SOCE. Therefore, Y361 in STIM1 represents a novel target for limiting SOCE-associated vascular leak.
authors.affiliation: Department of Pharmacology and Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA.
authors.forename: Pascal
authors.initials: P
authors.lastname: Yazbeck
authors.affiliation: Department of Pharmacology and Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA.|Department of Pharmaceutical Sciences, College of Pharmacy, Chicago State University, Chicago, IL 60628, USA.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Tauseef
authors.affiliation: Department of Pharmacology and Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Kruse
authors.affiliation: Department of Pharmacology and Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA.
authors.forename: Md-Ruhul
authors.initials: MR
authors.lastname: Amin
authors.affiliation: Department of Pharmacology and Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA.
authors.forename: Rayees
authors.initials: R
authors.lastname: Sheikh
authors.affiliation: Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.
authors.forename: Stefan
authors.initials: S
authors.lastname: Feske
authors.affiliation: Department of Pharmacology and Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA.
authors.forename: Yulia
authors.initials: Y
authors.lastname: Komarova
authors.affiliation: Department of Pharmacology and Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA.
authors.forename: Dolly
authors.initials: D
authors.lastname: Mehta
mesh_terms: D000818:Animals; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D004721:Endoplasmic Reticulum / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism; D051418:Focal Adhesion Kinase 2 / Q000378:metabolism*; D006801:Humans; D051379:Mice; D009154:Mutation; D009363:Neoplasm Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000071740:ORAI1 Protein / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D000071737:Stromal Interaction Molecule 1 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D009363:Neoplasm Proteins; D000071740:ORAI1 Protein; C103530:STIM1 protein, human; D000071737:Stromal Interaction Molecule 1; D014443:Tyrosine; D051418:Focal Adhesion Kinase 2; C103547:PTK2B protein, human; D002118:Calcium