... that membrane tubulation at borreliae-containing phagosomes, a process suggested earlier as a mechanism leading to phagosome compaction but hard to visualize in live-cell imaging, is apparently a frequent phenomenon. Finally, we demonstrate that the endoplasmic reticulum (ER) forms multiple STIM1-positive...

... Chen; Claude Ferec; Thierry Capiod; Olivier Mignen ABSTRACT Since deregulation of intracellular Ca 2+ can lead to intracellular trypsin activation, and stromal interaction molecule-1 (STIM1) protein is the main regulator of Ca 2+ homeostasis in pancreatic acinar cells, we explored the Ca 2+ signaling...

.... Dipeptides [glycyl-L-phenylalanine 2-naphthylamide (GPN) and L-leucyl-L-leucine methyl ester] that are inducers of lysosomal membrane permeabilization (LMP) uncoupled endoplasmic reticulum Ca 2+ -store depletion from SOCE by interfering with Stim1 oligomerization and/or Stim1 activation of Orai. Similarly...

...Liling Niu; Fuyun Wu; Kaili Li; Jing Li; Shenyuan L. Zhang; Junjie Hu; Qian Wang ABSTRACT Store-operated Ca 2+ entry (SOCE) is critical for numerous Ca 2+ -related processes. The activation of SOCE requires engagement between stromal interaction molecule 1 (STIM1) molecules on the endoplasmic...

... signaling competence . Dev. Cell   33 , 549 - 561 . 10.1016/j.devcel.2015.04.028 Korzeniowski , M. K. , Popovic , M. A. , Szentpetery , Z. , Varnai , P. , Stojilkovic , S. S. and Balla , T. ( 2009 ). Dependence of STIM1/Orai1-mediated calcium entry on plasma membrane...

..., but RASSF4 required coexpression with PIP5KIγ to increase plasma membrane PtdIns(4,5) P 2 . Effects on the several steps of store-operated calcium entry (SOCE) were not explained by plasma membrane phosphoinositide increases alone. PIP5KIβ and RASSF4 increased STIM1 proximity to the plasma membrane...

...Sang Kwon Lee; Min-hsun Lee; Su Ji Jeong; Xianan Qin; Ah Reum Lee; Hyokeun Park; Chan Young Park ABSTRACT Store-operated Ca 2+ entry (SOCE) is a major Ca 2+ influx pathway that is controlled by the ER Ca 2+ sensor STIM1. Abnormal activation of STIM1 directly influences Ca 2+ influx, resulting...

... channels of TRPC1 with TRPC4 or TRPC5. This possibility was explored in PC12 cells and guinea pig AM cells. Proximity ligation assay (PLA) revealed that when exogenously expressed in PC12 cells, TRPC1 forms a heteromeric channel with TRPC4, but not with TRPC5, in a STIM1-dependent manner. The heteromeric...

...Esther Lopez; Irene Frischauf; Isaac Jardin; Isabella Derler; Martin Muik; Carlos Cantonero; Gines M. Salido; Tarik Smani; Juan A. Rosado; Pedro C. Redondo ABSTRACT Stromal interaction molecule 1 (STIM1) is one of the key elements for the activation of store-operated Ca 2+ entry (SOCE). Hence...

...Marek K. Korzeniowski; Eva Wisniewski; Barbara Baird; David A. Holowka; Tamas Balla ABSTRACT Decreased luminal endoplasmic reticulum (ER) Ca 2+ concentration triggers oligomerization and clustering of the ER Ca 2+ sensor STIM1 to promote its association with plasma membrane Orai1 Ca 2+ channels...

...Rawad Hodeify; Senthil Selvaraj; Jennifer Wen; Abdelilah Arredouani; Satanay Hubrack; Maya Dib; Sara N. Al-Thani; Timothy McGraw; Khaled Machaca ABSTRACT The key proteins mediating store-operated Ca 2+ entry (SOCE) are the endoplasmic reticulum (ER) Ca 2+ sensor STIM1 and the plasma membrane Ca 2...

...Eulalia Pozo-Guisado; Vanessa Casas-Rua; Patricia Tomas-Martin; Aida M. Lopez-Guerrero; Alberto Alvarez-Barrientos; Francisco Javier Martin-Romero Summary STIM1 (stromal interaction molecule 1) is a key regulator of store-operated calcium entry (SOCE). Upon depletion of Ca 2+ concentration within...

... through intricate coordination between the Ca 2+ sensor on the ER membrane (stromal interaction molecule 1, STIM1) and the plasma membrane channel Orai1. When Ca 2+ stores are depleted, STIM1 oligomerizes and physically interacts with Orai1 through its SOAR/CAD domain, resulting in Orai1 gating and Ca 2...

... is downregulated during mouse meiosis, but remains active in mature metaphase II eggs. SOCE inhibition is due to a decreased ability of the Ca 2+ sensor STIM1 to translocate to the cortical endoplasmic reticulum domain and due to internalization of Orai1. Reversing SOCE downregulation by overexpression of STIM1...

...) in vivo and thus regulates fluid secretion. In Cav1 −/− mouse SG, agonist-stimulated Ca 2+ entry and fluid secretion are significantly reduced. Microdomain localization of TRPC1 and interaction with its regulatory protein, STIM1, are disrupted in Cav1 −/− SG acinar cells, whereas Orai1–STIM1 interaction...

... cells. In the present study, we find that association of the endoplasmic reticulum (ER) Ca 2+ sensor, STIM1, and the store-operated Ca 2+ channel, Orai1, stimulated by thapsigargin-mediated ER store depletion, is enhanced by overexpression of PIP5KIβ and inhibited by overexpression of PIP5KIγ...

..., STIM1, a transmembrane protein located in the endoplasmic reticulum (ER), aggregates and relocates close to the plasma membrane (PM) where it activates store-operated calcium channels (SOCs). Although STIM1 was early defined as a phosphoprotein, the contribution of the phosphorylation has been elusive...

... stimulation and depleted Ca 2+ stores (either due to IP3R-mediated Ca 2+ release or Ca 2+ uptake inhibition) work in concert to activate La 3+ -resistant Ca 2+ entry. This Ca 2+ entry was inhibited by genistein. In addition, BCR-mediated Ca 2+ entry was completely abolished in Stim1-deficient DT40 cells...

...Jeremy T. Smyth; Wayne I. DeHaven; Gary S. Bird; James W. Putney, Jr Stim1 responds to depletion of ER Ca 2+ stores by rearranging from tubular structures throughout the ER into punctate structures near the plasma membrane, where it activates Orai store-operated Ca 2+ entry (SOCE) channels. However...

... proposed, and there has been considerable interest in the possibility that TRP channels function as store-operated channels. However, in the past two years, two major players in both the signaling and permeation mechanisms for store-operated channels have been discovered: Stim1 and the Orai proteins. Stim1...