Show simple item record

dc.contributor.authorShen, Yihan
dc.contributor.authorThillaiappan, Nagendra Babu
dc.contributor.authorTaylor, Colin
dc.date.accessioned2021-02-02T00:32:00Z
dc.date.available2021-02-02T00:32:00Z
dc.date.issued2021-03-09
dc.identifier.issn0027-8424
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/316988
dc.description.abstractIncreases in cytosolic Ca2+ concentration regulate diverse cellular activities and are usually evoked by opening of Ca2+ channels in intracellular Ca2+ stores and the plasma membrane (PM). For the many signals that evoke formation of inositol 1,4,5-trisphosphate (IP3), IP3 receptors coordinate the contributions of these two Ca2+ sources by mediating Ca2+ release from the endoplasmic reticulum (ER). Loss of Ca2+ from the ER then activates store-operated Ca2+ entry (SOCE) by causing dimers of STIM1 to cluster and unfurl cytosolic domains that interact with the PM Ca2+ channel, Orai1, causing its pore to open. The relative concentrations of STIM1 and Orai1 are important, but most analyses of their interactions use overexpressed proteins that perturb the stoichiometry. We tagged endogenous STIM1 with EGFP using CRISPR/Cas9. SOCE evoked by loss of ER Ca2+ was unaffected by the tag. Step-photobleaching analysis of cells with empty Ca2+ stores revealed an average of 14.5 STIM1 molecules within each sub-PM punctum. The fluorescence intensity distributions of immunostained Orai1 puncta were minimally affected by store depletion, and similar for Orai1 colocalized with STIM1 puncta or remote from them. We conclude that each native SOCE complex is likely to include only a few STIM1 dimers associated with a single Orai1 channel. Our results, demonstrating that STIM1 does not assemble clusters of interacting Orai channels, suggest mechanisms for digital regulation of SOCE by local depletion of the ER.
dc.format.mediumPrint
dc.languageeng
dc.publisherProceedings of the National Academy of Sciences
dc.rightsAll rights reserved
dc.subjectHela Cells
dc.subjectEndoplasmic Reticulum
dc.subjectHumans
dc.subjectCalcium
dc.subjectPhosphatidylinositol Phosphates
dc.subjectNeoplasm Proteins
dc.subjectCalcium Signaling
dc.subjectProtein Multimerization
dc.subjectStromal Interaction Molecule 1
dc.subjectORAI1 Protein
dc.titleThe store-operated Ca2+ entry complex comprises a small cluster of STIM1 associated with one Orai1 channel.
dc.typeArticle
prism.issueIdentifier10
prism.publicationDate2021
prism.publicationNameProc Natl Acad Sci U S A
prism.volume118
dc.identifier.doi10.17863/CAM.64100
dcterms.dateAccepted2021-01-30
rioxxterms.versionofrecord10.1073/pnas.2010789118
rioxxterms.versionAM
rioxxterms.licenseref.urihttp://www.rioxx.net/licenses/all-rights-reserved
rioxxterms.licenseref.startdate2021-03
dc.contributor.orcidShen, Yihan [0000-0003-0504-0194]
dc.contributor.orcidThillaiappan, Nagendra Babu [0000-0001-5641-4067]
dc.contributor.orcidTaylor, Colin [0000-0001-7771-1044]
dc.identifier.eissn1091-6490
rioxxterms.typeJournal Article/Review
pubs.funder-project-idWellcome Trust (101844/Z/13/Z)
pubs.funder-project-idBiotechnology and Biological Sciences Research Council (BB/P005330/1)
cam.issuedOnline2021-03-01
cam.orpheus.successMon Mar 15 07:30:58 GMT 2021 - Embargo updated
cam.orpheus.counter5
rioxxterms.freetoread.startdate2021-09-30


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record