Abstract
The STIM1–ORAI1 pathway of store-operated Ca2+ entry is an essential component of cellular Ca2+ signalling1. STIM1 senses depletion of intracellular Ca2+ stores in response to physiological stimuli, and relocalizes within the endoplasmic reticulum to plasma-membrane-apposed junctions, where it recruits and gates open plasma membrane ORAI1 Ca2+ channels. Here we use a genome-wide RNA interference screen in HeLa cells to identify filamentous septin proteins as crucial regulators of store-operated Ca2+ entry. Septin filaments and phosphatidylinositol-4,5-bisphosphate (also known as PtdIns(4,5)P2) rearrange locally at endoplasmic reticulum–plasma membrane junctions before and during formation of STIM1–ORAI1 clusters, facilitating STIM1 targeting to these junctions and promoting the stable recruitment of ORAI1. Septin rearrangement at junctions is required for PtdIns(4,5)P2 reorganization and efficient STIM1–ORAI1 communication. Septins are known to demarcate specialized membrane regions such as dendritic spines, the yeast bud and the primary cilium, and to serve as membrane diffusion barriers and/or signalling hubs in cellular processes such as vesicle trafficking, cell polarity and cytokinesis2,3,4. Our data show that septins also organize the highly localized plasma membrane domains that are important in STIM1–ORAI1 signalling, and indicate that septins may organize membrane microdomains relevant to other signalling processes.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Rent or buy this article
Prices vary by article type
from$1.95
to$39.95
Prices may be subject to local taxes which are calculated during checkout





Similar content being viewed by others
References
Hogan, P. G., Lewis, R. S. & Rao, A. Molecular basis of calcium signaling in lymphocytes: STIM and ORAI. Annu. Rev. Immunol. 28, 491–533 (2010)
Estey, M. P., Kim, M. S. & Trimble, W. S. Septins. Curr. Biol. 21, R384–R387 (2011)
Caudron, F. & Barral, Y. Septins and the lateral compartmentalization of eukaryotic membranes. Dev. Cell 16, 493–506 (2009)
Mostowy, S. & Cossart, P. Septins: the fourth component of the cytoskeleton. Nature Rev. Mol. Cell Biol. 13, 183–194 (2012)
Hogan, P. G., Chen, L., Nardone, J. & Rao, A. Transcriptional regulation by calcium, calcineurin, and NFAT. Genes Dev. 17, 2205–2232 (2003)
Feske, S. et al. A mutation in Orai1 causes immune deficiency by abrogating CRAC channel function. Nature 441, 179–185 (2006)
Gwack, Y. et al. A genome-wide Drosophila RNAi screen identifies DYRK-family kinases as regulators of NFAT. Nature 441, 646–650 (2006)
Sharma, S. et al. Dephosphorylation of the nuclear factor of activated T cells (NFAT) transcription factor is regulated by an RNA-protein scaffold complex. Proc. Natl Acad. Sci. USA 108, 11381–11386 (2011)
Liou, J. et al. STIM is a Ca2+ sensor essential for Ca2+-store-depletion-triggered Ca2+ influx. Curr. Biol. 15, 1235–1241 (2005)
Zhou, Y. et al. STIM1 gates the store-operated calcium channel ORAI1 in vitro . Nature Struct. Mol. Biol. 17, 112–116 (2010)
Huang, G. N. et al. STIM1 carboxyl-terminus activates native SOC, I crac and TRPC1 channels. Nature Cell Biol. 8, 1003–1010 (2006)
Muik, M. et al. A cytosolic homomerization and a modulatory domain within STIM1 C terminus determine coupling to ORAI1 channels. J. Biol. Chem. 284, 8421–8426 (2009)
Muik, M. et al. Dynamic coupling of the putative coiled-coil domain of ORAI1 with STIM1 mediates ORAI1 channel activation. J. Biol. Chem. 283, 8014–8022 (2008)
Zhang, S. L. et al. Store-dependent and -independent modes regulating Ca2+ release-activated Ca2+ channel activity of human Orai1 and Orai3. J. Biol. Chem. 283, 17662–17671 (2008)
Hu, Q., Nelson, W. J. & Spiliotis, E. T. Forchlorfenuron alters mammalian septin assembly, organization, and dynamics. J. Biol. Chem. 283, 29563–29571 (2008)
DeMay, B. S., Meseroll, R. A., Occhipinti, P. & Gladfelter, A. S. Cellular requirements for the small molecule forchlorfenuron to stabilize the septin cytoskeleton. Cytoskeleton (Hoboken) 67, 383–399 (2010)
Li, Z. et al. Mapping the interacting domains of STIM1 and Orai1 in Ca2+ release-activated Ca2+ channel activation. J. Biol. Chem. 282, 29448–29456 (2007)
Park, C. Y. et al. STIM1 clusters and activates CRAC channels via direct binding of a cytosolic domain to Orai1. Cell 136, 876–890 (2009)
Walsh, C. M. et al. Role of phosphoinositides in STIM1 dynamics and store-operated calcium entry. Biochem. J. 425, 159–168 (2010)
Ercan, E. et al. A conserved, lipid-mediated sorting mechanism of yeast Ist2 and mammalian STIM proteins to the peripheral ER. Traffic 10, 1802–1818 (2009)
Liou, J., Fivaz, M., Inoue, T. & Meyer, T. Live-cell imaging reveals sequential oligomerization and local plasma membrane targeting of stromal interaction molecule 1 after Ca2+ store depletion. Proc. Natl Acad. Sci. USA 104, 9301–9306 (2007)
Zhang, J. et al. Phosphatidylinositol polyphosphate binding to the mammalian septin H5 is modulated by GTP. Curr. Biol. 9, 1458–1467 (1999)
Bertin, A. et al. Phosphatidylinositol-4,5-bisphosphate promotes budding yeast septin filament assembly and organization. J. Mol. Biol. 404, 711–731 (2010)
Várnai, P. & Balla, T. Visualization of phosphoinositides that bind pleckstrin homology domains: calcium- and agonist-induced dynamic changes and relationship to myo-[3H]inositol-labeled phosphoinositide pools. J. Cell Biol. 143, 501–510 (1998)
Stauffer, T. P., Ahn, S. & Meyer, T. Receptor-induced transient reduction in plasma membrane PtdIns(4,5)P2 concentration monitored in living cells. Curr. Biol. 8, 343–346 (1998)
Yang, Y. M. et al. Septins regulate developmental switching from microdomain to nanodomain coupling of Ca2+ influx to neurotransmitter release at a central synapse. Neuron 67, 100–115 (2010)
Hu, Q. et al. A septin diffusion barrier at the base of the primary cilium maintains ciliary membrane protein distribution. Science 329, 436–439 (2010)
Tada, T. et al. Role of septin cytoskeleton in spine morphogenesis and dendrite development in neurons. Curr. Biol. 17, 1752–1758 (2007)
Oh-Hora, M. et al. Dual functions for the endoplasmic reticulum calcium sensors STIM1 and STIM2 in T cell activation and tolerance. Nature Immunol. 9, 432–443 (2008)
Grynkiewicz, G., Poenie, M. & Tsien, R. Y. A new generation of Ca2+ indicators with greatly improved fluorescence properties. J. Biol. Chem. 260, 3440–3450 (1985)
Acknowledgements
We thank C. Shamu, S. Rudnicki, S. Johnston and D. Wrobel for screening support; A. Carpenter and M. Bray for CellProfiler optimization; P. Meraner and Y. Zhou for cell lines and constructs; S. Schmid, J. Fitzpatrick and the Waitt Advanced Biophotonics Center at the Salk Institute for access to TIRF microscopes; C. Junker for the RFP–ER construct; S. Field for the PLCδ-PH–eGFP plasmid; and S. Schmid for manuscript review. The work was supported by National Institutes of Health (NIH) R01 grants AI040127 and AI084167(to A.R. and P.G.H.), NIH RC4 grant AI092763 (to A.R. and S.S.); a Fellowship from the Canadian Institutes for Health Research and a Special Fellowship from The Leukemia & Lymphoma Society (to S.S.); postdoctoral fellowship QU298/1-1 from the Deutsche Forschungsgemeinschaft (to A.Q.); NIH grant K08 HL107451 (to M.J.); a postdoctoral scholarship from the Knut & Alice Wallenberg Foundation (to R.N.); NIH R01 grant R01GM73165 (to S. Schmid, which supports M.M.).
Author information
Authors and Affiliations
Contributions
The genome-wide screen was designed, optimized and performed by S.S. with assistance from B.B.; S.S. validated septins as regulators of NFAT, store-operated Ca2+ entry, STIM1–ORAI1 colocalization and ORAI1 cluster formation, with assistance from G.M.F. for confocal imaging, CellProfiler analyses and qRT–PCR. A.Q. performed single-cell Ca2+ imaging, electrophysiology, TIRFM, STIM1–ORAI1 colocalization, line-scan analysis and FCF experiments, with assistance from M.M. for TIRF microscopy. M.J. and R.N. performed bioinformatic analyses. P.G.H. and A.R. provided overall direction and supervised project planning and execution. S.S., A.Q., P.G.H. and A.R. wrote the manuscript with input from other authors.
Corresponding authors
Ethics declarations
Competing interests
A.R. and P.G.H. are founders of Calcimedica, Inc (La Jolla, California). The remaining authors state that they have no competing interests.
Supplementary information
Supplementary Information
This file contains Supplementary Figures 1-10, Supplementary Methods, Supplementary Tables 1-2, a Supplementary Discussion, Supplementary References and the legend for the Supplementary Data (see separate file). (PDF 3259 kb)
Supplementary Data
This file contains the data for the candidate regulators of NFAT nuclear import (see Supplementary Information file for legend). (XLS 213 kb)
Rights and permissions
About this article
Cite this article
Sharma, S., Quintana, A., Findlay, G. et al. An siRNA screen for NFAT activation identifies septins as coordinators of store-operated Ca2+ entry. Nature 499, 238–242 (2013). https://doi.org/10.1038/nature12229
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/nature12229
This article is cited by
-
Neuronal Store-Operated Calcium Channels
Molecular Neurobiology (2023)
-
The tumor suppressor kinase DAPK3 drives tumor-intrinsic immunity through the STING–IFN-β pathway
Nature Immunology (2021)
-
Septins, a cytoskeletal protein family, with emerging role in striated muscle
Journal of Muscle Research and Cell Motility (2021)
-
Septins organize endoplasmic reticulum-plasma membrane junctions for STIM1-ORAI1 calcium signalling
Scientific Reports (2019)
-
Calcium sensing by the STIM1 ER-luminal domain
Nature Communications (2018)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.