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Nuclear pore disassembly from endoplasmic reticulum membranes promotes Ca 2+ signalling competency
Author(s) -
Boulware Michael J.,
Marchant Jonathan S.
Publication year - 2008
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2008.153379
Subject(s) - endoplasmic reticulum , nuclear pore , microbiology and biotechnology , nucleoporin , organelle , cytosol , chemistry , cytoplasm , stim1 , biophysics , biology , biochemistry , cell nucleus , nuclear transport , enzyme
The functionality of the endoplasmic reticulum (ER) as a Ca 2+ storage organelle is supported by families of Ca 2+ pumps, buffers and channels that regulate Ca 2+ fluxes between the ER lumen and cytosol. Although many studies have identified heterogeneities in Ca 2+ fluxes throughout the ER, the question of how differential functionality of Ca 2+ 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 Ca 2+ signalling activity, an inhibitory influence relieved by heterogeneous dissociation of nucleoporins to yield NPC‐denuded ER domains competent at Ca 2+ 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.