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Store depletion induces Gαq‐mediated PLCβ1 activity to stimulate TRPC1 channels in vascular smooth muscle cells
Author(s) -
Shi Jian,
Miralles Francesc,
Birnbaumer Lutz,
Large William A.,
Albert Anthony P.
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.15-280271
Subject(s) - trpc1 , trpc , transient receptor potential channel , microbiology and biotechnology , protein kinase c , cyclopiazonic acid , chemistry , vascular smooth muscle , phosphorylation , endoplasmic reticulum , biology , biochemistry , endocrinology , receptor , smooth muscle
Depletion of sarcoplasmic reticulum (SR) Ca 2+ stores activates store‐operated channels (SOCs) composed of canonical transient receptor potential (TRPC) 1 proteins in vascular smooth muscle cells (VSMCs), which contribute to important cellular functions. We have previously shown that PKC is obligatory for activation of TRPC1 SOCs in VSMCs, and the present study investigates if the classic phosphoinositol signaling pathway involving Gαq‐mediated PLC activity is responsible for driving PKC‐dependent channel gating. The G‐protein inhibitor GDP‐β‐S, anti‐Gαq antibodies, the PLC inhibitor U73122, and the PKC inhibitor GF109203X all inhibited activation of TRPC 1 SOCs, and U73122 and GF109203X also reduced store‐operated PKC‐dependent phosphorylation of TRPC1 proteins. Three distinct SR Ca 2+ store‐depleting agents, 1,2‐bis (2‐aminophenoxy) ethane‐ N,N,N',N' ‐tetraacetic acid acetoxymethyl ester, cyclopiazonic acid, and N,N,N',N' ‐tetrakis(2‐pyridylmethyl)ethane‐1,2‐diamineed, induced trans‐locations of the fluorescent biosensor GFP‐PLCδ1‐PH from the cell membrane to the cytosol, which were inhibited by U73122. Knockdown of PLCβ1 with small hairpin RNA reduced both store‐operated PLC activity and stimulation of TRPC1 SOCs. Immunoprecipitation studies and proximity ligation assays revealed that store depletion induced interactions between TRPC 1 and Gαq, and TRPC 1 andPLCβ1. We propose a novel activation mechanism for TRPC 1 SOCs in VSMCs, in which store depletion induces formation of TRPC1‐Gαq‐PLCβ1 complexes that lead to PKC stimulation and channel gating.—Shi, J., Miralles, F., Birnbaumer, L., Large, W. A., Albert, A. P. Store depletion induces Gαq‐mediated PLCβ1 activity to stimulate TRPC1 channels in vascular smooth muscle cells. FASEB J. 30, 702‐715 (2016). www.fasebj.org