title: STIM1 phosphorylation triggered by epidermal growth factor mediates cell migration.
abstract: STIM1 is a key regulator of store-operated calcium entry (SOCE), and therefore a mediator of Ca²⁺ entry-dependent cellular events. Phosphorylation of STIM1 at ERK1/2 target sites has been described as enhancing STIM1 activation during intracellular Ca²⁺ emptying triggered by the inhibition of the sarco(endo)plasmic Ca²⁺ -ATPase with thapsigargin. However, no physiological function is known for this specific phosphorylation. The present study examined the role of STIM1 phosphorylation in cell signaling triggered by EGF. Using a human endometrial adenocarcinoma cell line (Ishikawa cells) EGF or H-Ras(G12V), an active mutant of H-Ras, was found to trigger STIM1 phosphorylation at residues Ser575, Ser608, and Ser621, and this process was sensitive to PD0325901, an inhibitor of ERK1/2. Both, ERK1/2 activation and STIM1 phosphorylation took place in the absence of extracellular Ca²⁺, indicating that both events are upstream steps for Ca²⁺entry activation. Also, EGF triggered the dissociation of STIM1 from EB1 (a regulator of microtubule plus-ends) in a manner similar to that reported for the activation of STIM1 by thapsigargin. Migration of the Ishikawa cells was impaired when STIM1 phosphorylation was targeted by Ser-to-Ala substitution mutation of ERK1/2 target sites. This effect was also observed with the Ca²⁺ channel blocker SKF96365. Phosphomimetic mutation of STIM1 restored the migration to levels similar to that found for STIM1-wild type. Finally, the increased vimentin expression and relocalization of E-cadherin triggered by EGF were largely inhibited by targeting STIM1 phosphorylation, while STIM1-S575E/S608E/S621E normalized the profiles of these two EMT markers.
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Life Sciences, University of Extremadura, Badajoz, Spain.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Casas-Rua
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Life Sciences, University of Extremadura, Badajoz, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Tomas-Martin
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Life Sciences, University of Extremadura, Badajoz, Spain.
authors.forename: Aida M
authors.initials: AM
authors.lastname: Lopez-Guerrero
authors.affiliation: Department of Cell Biology, School of Life Sciences, University of Extremadura, Badajoz, Spain.
authors.forename: Ignacio S
authors.initials: IS
authors.lastname: Alvarez
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Life Sciences, University of Extremadura, Badajoz, Spain. Electronic address: epozo@unex.es.
authors.forename: Eulalia
authors.initials: E
authors.lastname: Pozo-Guisado
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Life Sciences, University of Extremadura, Badajoz, Spain. Electronic address: fjmartin@unex.es.
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Martin-Romero
mesh_terms: D001549:Benzamides / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D004159:Diphenylamine / Q000031:analogs & derivatives / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D008565:Membrane Proteins / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000378:metabolism*; D010766:Phosphorylation; D000071737:Stromal Interaction Molecule 1
chemical_list: D001549:Benzamides; D007093:Imidazoles; D008565:Membrane Proteins; D009363:Neoplasm Proteins; C103530:STIM1 protein, human; D000071737:Stromal Interaction Molecule 1; D004815:Epidermal Growth Factor; C506614:mirdametinib; D004159:Diphenylamine; C063159:1-(2-(3-(4-methoxyphenyl)propoxy)-4-methoxyphenylethyl)-1H-imidazole; D002118:Calcium
keywords: Calcium; EGF; ERK1/2; Migration; Phosphorylation; STIM1