title: Role of STIM1 in the surface expression of SARAF.
abstract: The store-operated Ca2+entry-associated regulatory factor (SARAF), a protein expressed both in the endoplasmic reticulum and the plasma membrane, has been presented as a STIM1-interacting protein with the ability to modulate intracellular Ca2+homeostasis. SARAF negatively modulates store-operated Ca2+entry (SOCE) by preventing STIM1 spontaneous activation and regulating STIM1-Orai1 complex formation. In addition, SARAF is a negative regulator of Ca2+entry through the arachidonate-regulated Ca2+(ARC) channels. Here we explored the possible role of the surface expression of SARAF on the location of STIM1 in the plasma membrane. In NG115-401L cells, lacking a detectable expression of native STIM1, transfection with pHluorin-STIM1, which is able to translocate to the cell surface, enhances the plasma membrane location of SARAF as compared to cells transfected with YFP-STIM1, lacking the ability to translocate to the cell surface. These findings suggest that the surface location of SARAF is dependent on the expression of STIM1 in the plasma membrane.
authors.affiliation: a Department of Physiology , Cellular Physiology Research Group, University of Extremadura , Cáceres , Spain.
authors.forename: Letizia
authors.initials: L
authors.lastname: Albarran
authors.affiliation: b Department of Animal Medicine , University of Extremadura , Cáceres , Spain.
authors.forename: Sergio
authors.initials: S
authors.lastname: Regodón
authors.affiliation: a Department of Physiology , Cellular Physiology Research Group, University of Extremadura , Cáceres , Spain.
authors.forename: Gines M
authors.initials: GM
authors.lastname: Salido
authors.affiliation: a Department of Physiology , Cellular Physiology Research Group, University of Extremadura , Cáceres , Spain.
authors.forename: Jose J
authors.initials: JJ
authors.lastname: Lopez
authors.affiliation: a Department of Physiology , Cellular Physiology Research Group, University of Extremadura , Cáceres , Spain.
authors.forename: Juan A
authors.initials: JA
authors.lastname: Rosado
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism*; D052139:Intracellular Calcium-Sensing Proteins; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D009363:Neoplasm Proteins / Q000378:metabolism*; D051381:Rats; D000071737:Stromal Interaction Molecule 1 / Q000378:metabolism*
chemical_list: D052139:Intracellular Calcium-Sensing Proteins; D008565:Membrane Proteins; D009363:Neoplasm Proteins; C572578:SARAF protein, human; C103530:STIM1 protein, human; D000071737:Stromal Interaction Molecule 1
keywords: Orai1; SARAF; STIM1; store-operated Ca2+ entry