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The closing and opening of TRPC channels by Homer1 and STIM1
Author(s) -
Yuan J. P.,
Lee K. P.,
Hong J. H.,
Muallem S.
Publication year - 2012
Publication title -
acta physiologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.591
H-Index - 116
eISSN - 1748-1716
pISSN - 1748-1708
DOI - 10.1111/j.1748-1716.2011.02319.x
Subject(s) - trpc , closing (real estate) , trpc5 , business , chemistry , neuroscience , transient receptor potential channel , biology , finance , biochemistry , receptor
Influx of Ca 2+ is a central component of the receptor‐evoked Ca 2+ signal. A ubiquitous form of Ca 2+ influx comes from Ca 2+ channels that are activated in response to depletion of the endoplasmic reticulum Ca 2+ stores and are thus named the store‐operated Ca 2+ ‐influx channels (SOCs). One form of SOC is the transient receptor potential canonical (TRPC) channels. A major question in the field of Ca 2+ signalling is the molecular mechanism that regulates the opening and closing of these channels. All TRPC channels have a Homer‐binding ligand and two conserved negative charges that interact with two terminal lysines of the stromal interacting molecule 1 (STIM1). The Homer and STIM1 sites are separated by only four amino acid residues. Based on available results, we propose a molecular mechanism by which Homer couples TRPC channels to IP 3 receptors (IP 3 Rs) to keep these channels in the closed state. Dissociation of the TRPCs‐Homer‐IP 3 Rs complex allows STIM1 access to the TRPC channels negative charges to gate open these channels.