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This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 586/12/2873    most recent jphysiol.2008.153379v1 Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Boulware, M. J. Articles by Marchant, J. S. PubMed PubMed Citation Articles by Boulware, M. J. Articles by Marchant, J. S. Related Collections Cellular

¹ Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN 55455, USA

The functionality of the endoplasmic reticulum (ER) as a Ca²⁺ storage organelle is supported by families of Ca²⁺ pumps, buffers and channels that regulate Ca²⁺ fluxes between the ER lumen and cytosol. Although many studies have identified heterogeneities in Ca²⁺ fluxes throughout the ER, the question of how differential functionality of Ca²⁺ channels is regulated within proximal regions of the same organelle is unresolved. Here, we studied the in vivo dynamics of an ER subdomain known as annulate lamellae (AL), a cytoplasmic nucleoporin-containing organelle widely used in vitro to study the mechanics of nuclear envelope breakdown. We show that nuclear pore complexes (NPCs) within AL suppress local Ca²⁺ signalling activity, an inhibitory influence relieved by heterogeneous dissociation of nucleoporins to yield NPC-denuded ER domains competent at Ca²⁺ signalling. Consequently, we propose a novel generalized role for AL – reversible attenuation of resident protein activity – such that regulated AL (dis)assembly via a kinase/phosphatase cycle allows cells to support rapid gain/loss-of-function transitions in cellular physiology.

(Received 29 February 2008; accepted after revision 25 April 2008; first published online 1 May 2008)
Corresponding author J. S. Marchant: Department of Pharmacology, University of Minnesota Medical School, 6–120 Jackson Hall, 321 Church St SE, Minneapolis, MN 55455, USA. Email: march029{at}umn.edu