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Acta Physiologica 2010; Volume 198, Supplement 677
Joint Meeting of the Scandinavian and German Physiological Societies
3/27/2010-3/30/2010
Copenhagen, Denmark
ROLE OF SGK1 DEPENDENT REGULATION OF ORAI1/STIM1 IN MIGRATION
Abstract number: P-SUN-83
GEHRING1 EM, BHANDARU1 M, SHUMILINA1 E, EICHENMULLER1 M, KUNERT1 A, PEINELT1 C, PENNER1 R, STOURNARAS1 C, LANG1 F
Aims: Migration requires cellular Ca2+ entry which may be accomplished by Orai1, the pore forming protein mediating the store operated, calcium release-activated calcium current (ICRAC). Upon depletion of the intracellular calcium stores Orai is activated by the calciumsensor molecule STIM1. Most recently, mast cell ICRAC and degranulation have been shown to critically depend on the serum- and glucocorticoid-inducible kinase 1 (SGK1). The present study thus explored the contribution of SGK1 to the regulation of Ca2+ dependent migration. Methods: Experiments were performed in human embryonic kidney (HEK) cells stably expressing STIM1 and transfected with Orai1 and/or SGK1. Orai1 protein abundance in the cell membrane was determined by confocal microscopy, migration determined by transwell assays and cytosolic Ca2+ activity by Fura 2 fluorescence. In an additional series of experiments, migration was determined utilizing fibroblasts from SGK1 knockout mice (sgk1-/-) and fibroblasts from their wild-type littermates (sgk1+/+). Results: Surface expression of Orai1 was enhanced by additional expression of STIM1 and further enhanced by additional expression of constitutively active S422DSGK1. Expression of inactive K127NSGK1 decreased Orai surface expression. Similarly, migration was significantly enhanced by additional expression of STIM1 and S422DSGK1, and decreased by additional expression of K127NSGK1. Migration was significantly blunted in sgk1-/- fibroblasts as compared to sgk1+/+ fibroblasts. Conclusion: These observations disclose a decisive role for SGK1 in the regulation of Orai1, Ca2+ entry and migration.
To cite this abstract, please use the following information:
Acta Physiologica 2010; Volume 198, Supplement 677 :P-SUN-83