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Controllable Ion Channel Expression through Inducible Transient Transfection
Published on: February 17, 2017
TRPC channels as STIM1-regulated store-operated channels
Paul F Worley1, Weizhong Zeng, Guo N Huang
1Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. pworley@jhmi.edu
Cell Calcium
|May 23, 2007
Summary
Stromal interaction molecule 1 (STIM1) regulates store-operated channels (SOCs), including TRPC channels. STIM1 binding and translocation confirm TRPC1 and other TRPC channels function as SOCs, clarifying calcium influx mechanisms.
Area of Science:
- Cellular Biology
- Molecular Physiology
- Ion Channel Function
Background:
- Receptor-activated calcium (Ca2+) influx is crucial for cellular processes.
- Store-operated channels (SOCs) mediate a significant portion of this Ca2+ influx.
- The precise identity and regulation of SOCs, particularly TRPC channels, have been debated.
Purpose of the Study:
- To investigate the role of STIM1 in regulating TRPC channel function.
- To determine if TRPC channels, specifically TRPC1, function as SOCs.
- To elucidate the molecular mechanisms by which STIM1 controls Ca2+ influx.
Main Methods:
- STIM1 (stromal interaction molecule 1) was studied for its role in regulating Ca2+ influx channels.
- STIM1's interaction with various TRPC (Transient Receptor Potential Canonical) channels was analyzed.
- RNA interference (siRNA) was used to knock down STIM1 expression and observe its effect on channel activity.
Main Results:
- STIM1 directly binds to TRPC1, TRPC2, TRPC4, and TRPC5, regulating their activity.
- STIM1's C-terminus contains binding and gating domains, with the ERM domain interacting with TRPC channels.
- STIM1 depletion or inhibited translocation significantly reduced native SOC and TRPC1 activity, supporting TRPC1 as a SOC.
Conclusions:
- TRPC1 is confirmed to be a functional store-operated channel (SOC).
- STIM1 regulates TRPC1 and other TRPC channels (except TRPC7), establishing them as SOCs.
- This research provides a molecular definition of SOCs based on STIM1 regulation and TRPC channel involvement in Ca2+ influx.
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