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Martín-Aragón Baudel, Miguel A.S., Shi, Jian, Large, William A. and Albert, Anthony P. 
ORCID: https://orcid.org/0000-0002-3596-9634
(2020)
Obligatory role for PKCδ in PIP2-mediated activation of store-operated TRPC1 channels in vascular smooth muscle cells.
Journal of Physiology, 598 (18).
pp. 3911-3925.
ISSN 0022-3751
Abstract
Key points: In vascular smooth muscle cells (VSMCs), activation of Ca2+-permeable store-operated channels (SOCs) composed of canonical transient receptor potential channel 1 (TRPC1) subunits mediates Ca2+ entry pathways that regulate contraction, proliferation and migration, which are processes associated with vascular disease. Activation of TRPC1-based SOCs requires protein kinase C (PKC) activity, which is proposed to phosphorylate TRPC1 proteins to promote channel opening by phosphatidylinositol 4,5-bisphosphate (PIP2). We investigated the identity of the PKC isoform involved in activating TRPC1-based SOCs in rat mesenteric artery VSMCs. TRPC1-based SOCs were reduced by PKCδ inhibitors and knockdown of PKCδ expression. Store depletion induced interactions between TRPC1 and PKCδ and PKCδ-dependent phosphorylation of TRPC1. Furthermore, generation of store-operated interactions between PIP2 and TRPC1 and activation of TRPC1-based SOCs by PIP2 required PKCδ. These findings reveal that PKCδ activity has an obligatory role in activating TRPC1-based SOCs, through regulating PIP2-mediated channel opening. Abstract: In vascular smooth muscle cells (VMSCs), stimulation of Ca2+-permeable canonical transient receptor potential channel 1 (TRPC1)-based store-operated channels (SOCs) mediates Ca2+ entry pathways that regulate cell contraction, proliferation and migration, which are processes associated with vascular disease. It is therefore important to understand how TRPC1-based SOCs are activated. Stimulation of TRPC1-based SOCs requires protein kinase C (PKC) activity, with store-operated PKC-dependent phosphorylation of TRPC1 essential for channel opening by phosphatidylinositol 4,5-bisphosphate (PIP2). Experimental protocols used to activate TRPC1-based SOCs suggest that the PKC isoform involved requires diacylglycerol (DAG) but is Ca2+-insensitive, which are characteristics of the novel group of PKC isoforms (δ, ε, η, θ). Hence, the present study examined whether a novel PKC isoform(s) is involved in activating TRPC1-based SOCs in contractile rat mesenteric artery VSMCs. Store-operated whole-cell cation currents were blocked by Pico145, a highly selective and potent TRPC1/4/5 channel blocker and T1E3, a TRPC1 blocking antibody. PKCδ was expressed in VSMCs, and selective PKCδ inhibitory peptides and knockdown of PKCδ expression with morpholinos oligomers inhibited TRPC1-based SOCs. TRPC1 and PKCδ interactions and phosphorylation of TRPC1 induced by store depletion were both reduced by pharmacological inhibition and PKCδ knockdown. In addition, store-operated PIP2 and TRPC1 interactions were blocked by PKCδ inhibition, and PKCδ was required for PIP2-mediated activation of TRPC1 currents. These results identify the involvement of PKCδ in stimulation of TRPC1-based SOCs and highlight that store-operated PKCδ activity is obligatory for channel opening by PIP2, the probable activating ligand.
| Item Type: | Article |
|---|---|
| Additional Information: | Funding Information: This work was supported by the Biotechnology and Biological Sciences Research Council (BB/J007226/1 and BB/M018350/1 to AA). Publisher Copyright: © 2020 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society |
| Uncontrolled Keywords: | pip,pkc,store-operated channels,trpc1,vascular smooth muscle,physiology ,/dk/atira/pure/subjectarea/asjc/1300/1314 |
| Faculty \ School: | Faculty of Medicine and Health Sciences > Norwich Medical School |
| Related URLs: | |
| Depositing User: | LivePure Connector |
| Date Deposited: | 29 Oct 2024 09:30 |
| Last Modified: | 03 Nov 2024 07:30 |
| URI: | https://ueaeprints.uea.ac.uk/id/eprint/97243 |
| DOI: | 10.1113/JP279947 |
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