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Store‐operated Ca 2+ entry: Vesicle fusion or reversible trafficking and de novo conformational coupling?
Author(s) -
Rosado Juan A.,
Redondo Pedro C.,
Sage Stewart O.,
Pariente Jose A.,
Salido Ginés M.
Publication year - 2005
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.20399
Subject(s) - exocytosis , microbiology and biotechnology , vesicle fusion , secretion , lipid bilayer fusion , vesicle , actin cytoskeleton , actin , cytoskeleton , intracellular , second messenger system , chemistry , biology , biophysics , cell , membrane , biochemistry , synaptic vesicle
Store‐operated Ca 2+ entry (SOCE), a mechanism regulated by the filling state of the intracellular Ca 2+ stores, is a major pathway for Ca 2+ influx. Hypotheses to explain the communication between the Ca 2+ stores and plasma membrane (PM) have considered both the existence of small messenger molecules, such as a Ca 2+ ‐influx factor (CIF), and both stable and de novo conformational coupling between proteins in the Ca 2+ store and PM. Alternatively, a secretion‐like coupling model based on vesicle fusion and channel insertion in the PM has been proposed, which shares some properties with the de novo conformational coupling model, such as the role of the actin cytoskeleton and soluble N‐ethylmaleimide (NEM)‐sensitive‐factor attachment proteins receptor (SNARE) proteins. Here we review recent progress made in the characterization of the de novo conformational coupling and the secretion‐like coupling models for SOCE. We pay particular attention into the involvement of SNARE proteins and the actin cytoskeleton in both SOCE models. SNAREs are recognized as proteins involved in exocytosis, participating in vesicle transport, membrane docking, and fusion. As with secretion, a role for the cortical actin network in Ca 2+ entry has been demonstrated in a number of cell types. In resting cells, the cytoskeleton may prevent the interaction between the Ca 2+ stores and the PM, or preventing fusion of vesicles containing Ca 2+ channels with the PM. These are processes in which SNARE proteins might play a crucial role upon cell activation by directing a precise interaction between the membrane of the transported organelle and the PM. © 2005 Wiley‐Liss, Inc.