Transcription factor NF-κB regulates expression of pore-forming Ca2+ channel unit, Orai1, and its activator, STIM1, to control Ca2+ entry and affect cellular functions

J Biol Chem. 2012 Jan 20;287(4):2719-30. doi: 10.1074/jbc.M111.275925. Epub 2011 Nov 21.

Abstract

The serum and glucocorticoid-inducible kinase SGK1 increases the activity of Orai1, the pore forming unit of store-operated Ca(2+) entry, and thus influences Ca(2+)-dependent cellular functions such as migration. SGK1 further regulates transcription factor nuclear factor κB (NF-κB). This study explored whether SGK1 influences transcription of Orai1 and/or STIM1, the Orai1-activating Ca(2+) sensor. Orai1 and STIM1 transcript levels were decreased in mast cells from SGK1 knock-out mice and increased in HEK293 cells transfected with active (S422D)SGK1 but not with inactive (K127N)SGK1 or in (S422D)SGK1-transfected cells treated with the NF-κB inhibitor Wogonin (100 μm). Treatment with the stem cell factor enhanced transcript levels of STIM1 and Orai1 in sgk1(+/+) but not in sgk1(-/-) mast cells and not in sgk1(+/+) cells treated with Wogonin. Orai1 and STIM1 transcript levels were further increased in sgk1(+/+) and sgk1(-/-) mast cells by transfection with active NF-κB subunit p65 as well as in HEK293 cells by transfection with NF-κB subunits p65/p50 or p65/p52. They were decreased by silencing of NF-κB subunits p65, p50, or p52 or by NF-κB inhibitor Wogonin (100 μm). Luciferase assay and chromatin immunoprecipitation defined NF-κB-binding sites in promoter regions accounting for NF-κB sensitive genomic regulation of STIM1 and Orai1. Store-operated Ca(2+) entry was similarly increased by overexpression of p65/p50 or p65/p52 and decreased by treatment with Wogonin. Transfection of HEK293 cells with p65/p50 or p65/p52 further augmented migration. The present observations reveal powerful genomic regulation of Orai1/STIM1 by SGK1-dependent NF-κB signaling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Substitution
  • Animals
  • Calcium / metabolism*
  • Calcium Channels / biosynthesis*
  • Calcium Channels / genetics
  • Flavanones / pharmacology
  • Gene Expression Regulation / drug effects
  • Gene Expression Regulation / physiology*
  • HEK293 Cells
  • Humans
  • Immediate-Early Proteins / genetics
  • Immediate-Early Proteins / metabolism
  • Mast Cells / cytology
  • Mast Cells / metabolism*
  • Membrane Glycoproteins / biosynthesis*
  • Membrane Glycoproteins / genetics
  • Membrane Proteins / biosynthesis*
  • Membrane Proteins / genetics
  • Mice
  • Mice, Knockout
  • Mutation, Missense
  • NF-kappa B / antagonists & inhibitors
  • NF-kappa B / genetics
  • NF-kappa B / metabolism*
  • Neoplasm Proteins / biosynthesis*
  • Neoplasm Proteins / genetics
  • ORAI1 Protein
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism
  • Response Elements / physiology
  • Signal Transduction / drug effects
  • Signal Transduction / physiology
  • Stromal Interaction Molecule 1

Substances

  • Calcium Channels
  • Flavanones
  • Immediate-Early Proteins
  • Membrane Glycoproteins
  • Membrane Proteins
  • NF-kappa B
  • Neoplasm Proteins
  • ORAI1 Protein
  • ORAI1 protein, human
  • Orai1 protein, mouse
  • STIM1 protein, human
  • Stim1 protein, mouse
  • Stromal Interaction Molecule 1
  • Protein Serine-Threonine Kinases
  • serum-glucocorticoid regulated kinase
  • wogonin
  • Calcium