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Remodelling of the endoplasmic reticulum during store‐operated calcium entry
Author(s) -
Shen WeiWei,
Frieden Maud,
Demaurex Nicolas
Publication year - 2011
Publication title -
biology of the cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 85
eISSN - 1768-322X
pISSN - 0248-4900
DOI - 10.1042/bc20100152
Subject(s) - stim1 , trpc , orai1 , microbiology and biotechnology , endoplasmic reticulum , cytosol , calcium signaling , calcium , transient receptor potential channel , biology , voltage dependent calcium channel , biophysics , chemistry , receptor , intracellular , biochemistry , organic chemistry , enzyme
SOCE (store‐operated calcium entry) is a ubiquitous cellular mechanism linking the calcium depletion of the ER (endoplasmic reticulum) to the activation of PM (plasma membrane) Ca 2+ ‐permeable channels. The activation of SOCE channels favours the entry of extracellular Ca 2+ into the cytosol, thereby promoting the refilling of the depleted ER Ca 2+ stores as well as the generation of long‐lasting calcium signals. The molecules that govern SOCE activation comprise ER Ca 2+ sensors [STIM1 (stromal interaction molecule 1) and STIM2], PM Ca 2+ ‐permeable channels {Orai and TRPC [TRP (transient receptor potential) canonical]} and regulatory Ca 2+ ‐sensitive cytosolic proteins {CRACR2 [CRAC (Ca 2+ release‐activated Ca 2+ current) regulator 2]}. Upon Ca 2+ depletion of the ER, STIM molecules move towards the PM to bind and activate Orai or TRPC channels, initiating calcium entry and store refilling. This molecular rearrangement is accompanied by the formation of specialized compartments derived from the ER, the pre‐cER (cortical ER) and cER. The pre‐cER appears on the electron microscope as thin ER tubules enriched in STIM1 that extend along microtubules and that are devoid of contacts with the PM. The cER is located in immediate proximity to the PM and comprises thinner sections enriched in STIM1 and devoid of chaperones that might be dedicated to calcium signalling. Here, we review the molecular interactions and the morphological changes in ER structure that occur during the SOCE process.