Store‐operated interactions between plasmalemmal STIM1 and TRPC1 proteins stimulate PLCβ1 to induce TRPC1 channel activation in vascular smooth muscle cells

作者：Jian Shi, Francesc Miralles, Lutz Birnbaumer, W. A. Large, Anthony P. Albert · 发表于：The Journal of Physiology · 年份：2016 · DOI：10.1113/jp273302 · 被引用次数：37 · 研究领域：Ion Channels and Receptors、Postharvest Quality and Shelf Life Management、Phytochemicals and Antioxidant Activities

Key points Depletion of Ca 2+ stores activates store‐operated channels (SOCs), which mediate Ca 2+ 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 Ca 2+ entry pathways that regulate contractility, proliferation and migration. It is therefore important to...