Tags

Type your tag names separated by a space and hit enter

Store-operated interactions between plasmalemmal STIM1 and TRPC1 proteins stimulate PLCβ1 to induce TRPC1 channel activation in vascular smooth muscle cells.
J Physiol. 2017 02 15; 595(4):1039-1058.JP

Abstract

KEY POINTS

Depletion of Ca2+ stores activates store-operated channels (SOCs), which mediate Ca2+ entry pathways that regulate cellular processes such as contraction, proliferation and gene expression. In vascular smooth muscle cells (VSMCs), stimulation of SOCs composed of canonical transient receptor potential channel 1 (TRPC1) proteins requires G protein α q subunit (Gαq)/phospholipase C (PLC)β1/protein kinase C (PKC) activity. We studied the role of stromal interaction molecule 1 (STIM1) in coupling store depletion to this activation pathway using patch clamp recording, GFP-PLCδ1-PH imaging and co-localization techniques. Store-operated TRPC1 channel and PLCβ1 activities were inhibited by STIM1 short hairpin RNA (shRNA) and absent in TRPC1-/- cells, and store-operated PKC phosphorylation of TRPC1 was inhibited by STIM1 shRNA. Store depletion induced interactions between STIM1 and TRPC1, Gαq and PLCβ1, which required STIM1 and TRPC1. Similar effects were produced with noradrenaline. These findings identify a new activation mechanism of TRPC1-based SOCs in VSMCs, and a novel role for STIM1, where store-operated STIM1-TRPC1 interactions stimulate Gαq/PLCβ1/PKC activity to induce channel gating.

ABSTRACT

In vascular smooth muscle cells (VSMCs), stimulation of canonical transient receptor potential channel 1 (TRPC1) protein-based store-operated channels (SOCs) mediates Ca2+ entry pathways that regulate contractility, proliferation and migration. It is therefore important to understand how these channels are activated. Studies have shown that stimulation of TRPC1-based SOCs requires G protein α q subunit (Gαq)/phospholipase C (PLC)β1 activities and protein kinase C (PKC) phosphorylation, although it is unclear how store depletion stimulates this gating pathway. The present study examines this issue by focusing on the role of stromal interaction molecule 1 (STIM1), an endo/sarcoplasmic reticulum Ca2+ sensor. Store-operated TRPC1 channel activity was inhibited by TRPC1 and STIM1 antibodies and STIM1 short hairpin RNA (shRNA) in wild-type VSMCs, and was absent in TRPC1-/- VSMCs. Store-operated PKC phosphorylation of TRPC1 was reduced by knockdown of STIM1. Moreover, store-operated PLCβ1 activity measured with the fluorescent phosphatidylinositol 4,5-bisphosphate/inositol 1,4,5-trisphosphate biosensor GFP-PLCδ1-PH was reduced by STIM1 shRNA and absent in TRPC1-/- cells. Immunocytochemistry, co-immunoprecipitation and proximity ligation assays revealed that store depletion activated STIM1 translocation from within the cell to the plasma membrane (PM) where it formed STIM1-TRPC1 complexes, which then associated with Gαq and PLCβ1. Noradrenaline also evoked TRPC1 channel activity and associations between TRPC1, STIM1, Gαq and PLCβ1, which were inhibited by STIM1 knockdown. Effects of N-terminal and C-terminal STIM1 antibodies on TRPC1-based SOCs and STIM1 staining suggest that channel activation may involve insertion of STIM1 into the PM. The findings of the present study identify a new activation mechanism of TRPC1-based SOCs in VSMCs, and a novel role for STIM1, in which store-operated STIM1-TRPC1 interactions stimulate PLCβ1 activity to induce PKC phosphorylation of TRPC1 and channel gating.

Authors+Show Affiliations

Vascular Biology Research Centre, Molecular & Clinical Sciences Research Institute.Vascular Biology Research Centre, Molecular & Clinical Sciences Research Institute. Institute of Medical & Biomedical Education, St George's, University of London, London, UK.Neurobiology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA. Institute of Biomedical Research (BIOMED), School of Medical Sciences, Catholic University of Argentina, Buenos Aires, Argentina.Vascular Biology Research Centre, Molecular & Clinical Sciences Research Institute.Vascular Biology Research Centre, Molecular & Clinical Sciences Research Institute.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, N.I.H., Intramural

Language

eng

PubMed ID

27753095

Citation

Shi, Jian, et al. "Store-operated Interactions Between Plasmalemmal STIM1 and TRPC1 Proteins Stimulate PLCβ1 to Induce TRPC1 Channel Activation in Vascular Smooth Muscle Cells." The Journal of Physiology, vol. 595, no. 4, 2017, pp. 1039-1058.
Shi J, Miralles F, Birnbaumer L, et al. Store-operated interactions between plasmalemmal STIM1 and TRPC1 proteins stimulate PLCβ1 to induce TRPC1 channel activation in vascular smooth muscle cells. J Physiol. 2017;595(4):1039-1058.
Shi, J., Miralles, F., Birnbaumer, L., Large, W. A., & Albert, A. P. (2017). Store-operated interactions between plasmalemmal STIM1 and TRPC1 proteins stimulate PLCβ1 to induce TRPC1 channel activation in vascular smooth muscle cells. The Journal of Physiology, 595(4), 1039-1058. https://doi.org/10.1113/JP273302
Shi J, et al. Store-operated Interactions Between Plasmalemmal STIM1 and TRPC1 Proteins Stimulate PLCβ1 to Induce TRPC1 Channel Activation in Vascular Smooth Muscle Cells. J Physiol. 2017 02 15;595(4):1039-1058. PubMed PMID: 27753095.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Store-operated interactions between plasmalemmal STIM1 and TRPC1 proteins stimulate PLCβ1 to induce TRPC1 channel activation in vascular smooth muscle cells. AU - Shi,Jian, AU - Miralles,Francesc, AU - Birnbaumer,Lutz, AU - Large,William A, AU - Albert,Anthony P, Y1 - 2016/12/07/ PY - 2016/09/15/received PY - 2016/10/13/accepted PY - 2016/10/19/pubmed PY - 2017/9/2/medline PY - 2016/10/19/entrez KW - PLC KW - STIM1 KW - TRPC KW - vascular smooth muscle SP - 1039 EP - 1058 JF - The Journal of physiology JO - J Physiol VL - 595 IS - 4 N2 - KEY POINTS: Depletion of Ca2+ stores activates store-operated channels (SOCs), which mediate Ca2+ entry pathways that regulate cellular processes such as contraction, proliferation and gene expression. In vascular smooth muscle cells (VSMCs), stimulation of SOCs composed of canonical transient receptor potential channel 1 (TRPC1) proteins requires G protein α q subunit (Gαq)/phospholipase C (PLC)β1/protein kinase C (PKC) activity. We studied the role of stromal interaction molecule 1 (STIM1) in coupling store depletion to this activation pathway using patch clamp recording, GFP-PLCδ1-PH imaging and co-localization techniques. Store-operated TRPC1 channel and PLCβ1 activities were inhibited by STIM1 short hairpin RNA (shRNA) and absent in TRPC1-/- cells, and store-operated PKC phosphorylation of TRPC1 was inhibited by STIM1 shRNA. Store depletion induced interactions between STIM1 and TRPC1, Gαq and PLCβ1, which required STIM1 and TRPC1. Similar effects were produced with noradrenaline. These findings identify a new activation mechanism of TRPC1-based SOCs in VSMCs, and a novel role for STIM1, where store-operated STIM1-TRPC1 interactions stimulate Gαq/PLCβ1/PKC activity to induce channel gating. ABSTRACT: In vascular smooth muscle cells (VSMCs), stimulation of canonical transient receptor potential channel 1 (TRPC1) protein-based store-operated channels (SOCs) mediates Ca2+ entry pathways that regulate contractility, proliferation and migration. It is therefore important to understand how these channels are activated. Studies have shown that stimulation of TRPC1-based SOCs requires G protein α q subunit (Gαq)/phospholipase C (PLC)β1 activities and protein kinase C (PKC) phosphorylation, although it is unclear how store depletion stimulates this gating pathway. The present study examines this issue by focusing on the role of stromal interaction molecule 1 (STIM1), an endo/sarcoplasmic reticulum Ca2+ sensor. Store-operated TRPC1 channel activity was inhibited by TRPC1 and STIM1 antibodies and STIM1 short hairpin RNA (shRNA) in wild-type VSMCs, and was absent in TRPC1-/- VSMCs. Store-operated PKC phosphorylation of TRPC1 was reduced by knockdown of STIM1. Moreover, store-operated PLCβ1 activity measured with the fluorescent phosphatidylinositol 4,5-bisphosphate/inositol 1,4,5-trisphosphate biosensor GFP-PLCδ1-PH was reduced by STIM1 shRNA and absent in TRPC1-/- cells. Immunocytochemistry, co-immunoprecipitation and proximity ligation assays revealed that store depletion activated STIM1 translocation from within the cell to the plasma membrane (PM) where it formed STIM1-TRPC1 complexes, which then associated with Gαq and PLCβ1. Noradrenaline also evoked TRPC1 channel activity and associations between TRPC1, STIM1, Gαq and PLCβ1, which were inhibited by STIM1 knockdown. Effects of N-terminal and C-terminal STIM1 antibodies on TRPC1-based SOCs and STIM1 staining suggest that channel activation may involve insertion of STIM1 into the PM. The findings of the present study identify a new activation mechanism of TRPC1-based SOCs in VSMCs, and a novel role for STIM1, in which store-operated STIM1-TRPC1 interactions stimulate PLCβ1 activity to induce PKC phosphorylation of TRPC1 and channel gating. SN - 1469-7793 UR - https://www.unboundmedicine.com/medline/citation/27753095/Store_operated_interactions_between_plasmalemmal_STIM1_and_TRPC1_proteins_stimulate_PLCβ1_to_induce_TRPC1_channel_activation_in_vascular_smooth_muscle_cells_ L2 - https://doi.org/10.1113/JP273302 DB - PRIME DP - Unbound Medicine ER -