Related Experiment Video

Updated: Jun 8, 2026

Single-Cell Calcium Imaging for Studying the Activation of Calcium Ion Channels
07:17

Single-Cell Calcium Imaging for Studying the Activation of Calcium Ion Channels

Published on: December 13, 2024

STIM1-dependent and STIM1-independent function of transient receptor potential canonical (TRPC) channels tunes their

Kyu Pil Lee1, Joseph P Yuan, Insuk So

  • 1Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.

The Journal of Biological Chemistry
|October 8, 2010
PubMed

Insights

Transient Receptor Potential Canonical (TRPC) channels mediate calcium influx. This study reveals TRPC channels can function both dependently and independently of STIM1, enhancing their role in cellular signaling.

Area of Science:

  • Cellular Biology
  • Molecular Physiology
  • Ion Channel Function

Background:

  • Store-operated calcium (Ca2+) influx is crucial for receptor-evoked Ca2+ signaling.
  • Transient Receptor Potential Canonical (TRPC) channels are key mediators of receptor-stimulated Ca2+ influx.
  • The precise role of STIM1 in TRPC channel activation during receptor stimulation requires further elucidation.

Purpose of the Study:

  • To investigate the STIM1 dependence and independence of TRPC channel activation by receptor stimulation.
  • To characterize the function of TRPC channel mutants in response to STIM1 and receptor stimulation.
  • To elucidate the mechanisms underlying TRPC channel activation in calcium signaling.

Main Methods:

  • Generation and characterization of TRPC channel mutants.
  • Utilizing STIM1 and a charge-swap mutant STIM1(K684E,K685E) to probe channel activation.
  • Employing Orai1(R91W) to scavenge STIM1 and assess TRPC channel dependence.

Main Results:

  • TRPC channel mutants were activated by STIM1(K684E,K685E) but not by wild-type STIM1.
  • Wild-type TRPC channels showed STIM1 dependence, while mutants exhibited STIM1 independence.
  • Mutant TRPC channels were robustly activated by receptor stimulation, independent of STIM1.

Conclusions:

  • TRPC channels can operate as both STIM1-dependent and STIM1-independent signaling units.
  • This dual functionality enhances the versatility of TRPC channels in receptor-stimulated calcium influx.
  • Findings provide new insights into the complex regulation of calcium signaling pathways.

More Related Videos

Expression and Purification of the Human Lipid-sensitive Cation Channel TRPC3 for Structural Determination by Single-particle Cryo-electron Microscopy08:27

Expression and Purification of the Human Lipid-sensitive Cation Channel TRPC3 for Structural Determination by Single-particle Cryo-electron Microscopy

Published on: January 7, 2019

Controllable Ion Channel Expression through Inducible Transient Transfection10:00

Controllable Ion Channel Expression through Inducible Transient Transfection

Published on: February 17, 2017

Related Concept Videos

Mechanically-gated Ion Channels01:12

Mechanically-gated Ion Channels

Mechanically-gated ion channels are proteins found in eukaryotic and prokaryotic cell membranes that open in response to mechanical stress. Tension, compression, swelling, and shear stress can alter the conformation of the protein, opening a transmembrane channel that allows the passage of ions for signal transmission. In eukaryotes, mechanically-gated channels are distributed in several regions like the neurons, lungs, skin, bladder, and heart, where they play critical roles in numerous...
Mechanically-gated Ion Channels01:12

Mechanically-gated Ion Channels

Mechanically-gated ion channels are proteins found in eukaryotic and prokaryotic cell membranes that open in response to mechanical stress. Tension, compression, swelling, and shear stress can alter the conformation of the protein, opening a transmembrane channel that allows the passage of ions for signal transmission. In eukaryotes, mechanically-gated channels are distributed in several regions like the neurons, lungs, skin, bladder, and heart, where they play critical roles in numerous...
Feedback Regulation of Calcium Concentration01:27

Feedback Regulation of Calcium Concentration

Calcium is an essential signaling molecule required for various cellular functions. Calcium pumps and ion channels on cell and organellar membranes, such as those on the endoplasmic reticulum (ER), regulate calcium concentrations inside the cell. They remain closed, keeping the cytosolic calcium levels low at a resting state.
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Ligand-Gated Ion Channel Receptor: Gating Mechanism01:30

Ligand-Gated Ion Channel Receptor: Gating Mechanism

Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...
G-Protein Gated Ion Channels01:21

G-Protein Gated Ion Channels

GPCRs are primarily responsible for our sense of smell, taste, and vision.  The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response.
Sensory organs,...
Non-gated Ion Channels01:24

Non-gated Ion Channels

Ion channels are specialized proteins on the plasma membrane that allow charged ions to pass down their electrochemical gradient. Their main function is to maintain the membrane potential which is critical for cell viability. These channels are either gated or non-gated and can transport more than a thousand ions within milliseconds for the cellular event to occur.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.