title: The ER Stress Sensor PERK Coordinates ER-Plasma Membrane Contact Site Formation through Interaction with Filamin-A and F-Actin Remodeling.
abstract: Loss of ER Ca2+homeostasis triggers endoplasmic reticulum (ER) stress and drives ER-PM contact sites formation in order to refill ER-luminal Ca2+. Recent studies suggest that the ER stress sensor and mediator of the unfolded protein response (UPR) PERK regulates intracellular Ca2+fluxes, but the mechanisms remain elusive. Here, using proximity-dependent biotin identification (BioID), we identified the actin-binding protein Filamin A (FLNA) as a key PERK interactor. Cells lacking PERK accumulate F-actin at the cell edges and display reduced ER-PM contacts. Following ER-Ca2+store depletion, the PERK-FLNA interaction drives the expansion of ER-PM juxtapositions by regulating F-actin-assisted relocation of the ER-associated tethering proteins Stromal Interaction Molecule 1 (STIM1) and Extended Synaptotagmin-1 (E-Syt1) to the PM. Cytosolic Ca2+elevation elicits rapid and UPR-independent PERK dimerization, which enforces PERK-FLNA-mediated ER-PM juxtapositions. Collectively, our data unravel an unprecedented role of PERK in the regulation of ER-PM appositions through the modulation of the actin cytoskeleton.
authors.affiliation: Laboratory of Cell Death Research and Therapy, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, B-3000, Belgium.
authors.forename: Alexander R
authors.initials: AR
authors.lastname: van Vliet
authors.affiliation: Institut Jacques Monod-UMR 7592 CNRS-Université Paris Diderot, Paris Cedex 7, France.
authors.forename: Francesca
authors.initials: F
authors.lastname: Giordano
authors.affiliation: VIB Medical Biotechnology Center, UGent Department of Biochemistry, UGent, Gent B-9000, Belgium.
authors.forename: Sarah
authors.initials: S
authors.lastname: Gerlo
authors.affiliation: Laboratory of Angiogenesis and Vascular Metabolism, Department of Oncology, KU Leuven, Leuven B-3000, Belgium; Laboratory of Angiogenesis and Vascular Metabolism, Vesalius Research Center, VIB, Leuven B-3000, Belgium.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Segura
authors.affiliation: Laboratory of Cell Death Research and Therapy, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, B-3000, Belgium.
authors.forename: Sofie
authors.initials: S
authors.lastname: Van Eygen
authors.affiliation: Leuven Biostatistics and Statistical Bioinformatics Centre (L-BioStat), KU Leuven, Leuven, B-3000 Belgium.
authors.forename: Geert
authors.initials: G
authors.lastname: Molenberghs
authors.affiliation: Laboratory for Photochemistry and Spectroscopy, Department of Chemistry, KU Leuven, Leuven, B-3000 Belgium.
authors.forename: Susana
authors.initials: S
authors.lastname: Rocha
authors.affiliation: Institut Jacques Monod-UMR 7592 CNRS-Université Paris Diderot, Paris Cedex 7, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Houcine
authors.affiliation: Laboratory of Protein Phosphorylation and Proteomics, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, B-3000 Belgium; SyBioMa, KU Leuven, Leuven, B-3000 Belgium.
authors.forename: Rita
authors.initials: R
authors.lastname: Derua
authors.affiliation: Laboratory of Cell Death Research and Therapy, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, B-3000, Belgium.
authors.forename: Tom
authors.initials: T
authors.lastname: Verfaillie
authors.affiliation: Laboratory for Photochemistry and Spectroscopy, Department of Chemistry, KU Leuven, Leuven, B-3000 Belgium.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Vangindertael
authors.affiliation: Laboratory for Biomolecular Network Dynamics, Biochemistry, Department of Chemistry, KU Leuven, Leuven, B-3000 Belgium.
authors.forename: Herlinde
authors.initials: H
authors.lastname: De Keersmaecker
authors.affiliation: Laboratory of Protein Phosphorylation and Proteomics, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, B-3000 Belgium; SyBioMa, KU Leuven, Leuven, B-3000 Belgium.
authors.forename: Etienne
authors.initials: E
authors.lastname: Waelkens
authors.affiliation: VIB Medical Biotechnology Center, UGent Department of Biochemistry, UGent, Gent B-9000, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Tavernier
authors.affiliation: Laboratory for Photochemistry and Spectroscopy, Department of Chemistry, KU Leuven, Leuven, B-3000 Belgium.
authors.forename: Johan
authors.initials: J
authors.lastname: Hofkens
authors.affiliation: VIB Center for Brain & Disease Research, Department of Neurosciences & Leuven Institute for Neuroscience and Disease (LIND), KU Leuven, Leuven B-3000, Belgium.
authors.forename: Wim
authors.initials: W
authors.lastname: Annaert
authors.affiliation: Laboratory of Angiogenesis and Vascular Metabolism, Department of Oncology, KU Leuven, Leuven B-3000, Belgium; Laboratory of Angiogenesis and Vascular Metabolism, Vesalius Research Center, VIB, Leuven B-3000, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Carmeliet
authors.affiliation: Apoptosis Research Centre, NUI, Galway, Ireland.
authors.forename: Afshin
authors.initials: A
authors.lastname: Samali
authors.affiliation: Laboratory for Biomolecular Network Dynamics, Biochemistry, Department of Chemistry, KU Leuven, Leuven, B-3000 Belgium.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Mizuno
authors.affiliation: Laboratory of Cell Death Research and Therapy, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, B-3000, Belgium. Electronic address: patrizia.agostinis@kuleuven.be.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Agostinis
mesh_terms: D008841:Actin Cytoskeleton / Q000201:enzymology*; D000199:Actins / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D002462:Cell Membrane / Q000201:enzymology*; D004721:Endoplasmic Reticulum / Q000201:enzymology*; D059865:Endoplasmic Reticulum Stress; D064448:Filamins / Q000235:genetics / Q000378:metabolism*; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D009363:Neoplasm Proteins / Q000378:metabolism; D055503:Protein Multimerization; D021381:Protein Transport; D034622:RNA Interference; D015398:Signal Transduction; D000071737:Stromal Interaction Molecule 1 / Q000378:metabolism; D050863:Synaptotagmin I / Q000378:metabolism; D013997:Time Factors; D014162:Transfection; D056811:Unfolded Protein Response; D019892:eIF-2 Kinase / Q000235:genetics / Q000378:metabolism*
chemical_list: D000199:Actins; D002118:Calcium; D064448:Filamins; D009363:Neoplasm Proteins; D000071737:Stromal Interaction Molecule 1; D050863:Synaptotagmin I; D019892:eIF-2 Kinase; C578663:FLNA protein, human; C529499:FlnA protein, mouse; C103530:STIM1 protein, human; C494310:SYT1 protein, human; C460640:EIF2AK3 protein, human
keywords: ER-PM contact sites; FLNA; PERK; SOCE; STIM1; actin cytoskeleton; actin relocalization; calcium signaling; endoplasmic reticulum; extended-Synaptotagmin 1; plasma membrane; unfolded protein response