Related Experiment Video
Updated: Jul 15, 2025

12:49
Isolation, Culture, and Functional Characterization of Adult Mouse Cardiomyoctyes
Published on: September 24, 2013
24.5K
Channel Behavior and Voltage Gating of a Cx43 Mutant Simulating Preconditioning
Jose F Ek-Vitorin1, Diego Silva-Mendoza1, Tasha K Pontifex1
1Department of Physiology, University of Arizona, Tucson, Arizona, USA.
Bioelectricity
|September 25, 2023
Summary
Ischemic preconditioning affects Connexin 43 (Cx43) phosphorylation. A Cx43 mutant mimicking this phosphorylation showed altered hemichannel and gap junction properties, potentially preserving cell communication during ischemia.
Area of Science:
- Cardiovascular Biology
- Molecular Cell Biology
- Biophysics
Background:
- Ischemic preconditioning alters Connexin 43 (Cx43) phosphorylation and localization.
- Casein kinase 1 (CK1) and protein kinase C (PKC) phosphorylation of Cx43 are cardioprotective.
- The functional consequences of Cx43 phosphorylation mimicking preconditioning remain unclear.
Purpose of the Study:
- To investigate the channel characteristics of a Cx43 mutant mimicking CK1 and PKC phosphorylation associated with ischemic preconditioning.
- To analyze the electrical behavior of Cx43 at both single-channel and macroscopic levels.
Main Methods:
- Whole-cell patch-clamp recordings were utilized.
- Cells expressing a mutant Cx43 (Cx43pc) mimicking preconditioning phosphorylation were studied.
- Single-channel and macroscopic electrical behaviors were analyzed.
Main Results:
- Cx43pc hemichannels exhibited readily opening.
- Gap junction channels showed intermediate amplitudes compared to wild-type and CK1-phosphorylated Cx43.
- Voltage gating of Cx43pc gap junction channels was weaker than wild-type or CK1-phosphorylated forms.
Conclusions:
- Cx43 phosphorylation by PKC during ischemic preconditioning may lead to junctional channels insensitive to voltage.
- This insensitivity could preserve intercellular communication under ischemic conditions.
- Understanding Cx43 channel behavior is crucial for developing cardioprotective strategies.
Related Concept Videos
Ligand-Gated Ion Channel Receptor: Gating Mechanism
2.3K
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...
2.3K
G-Protein Gated Ion Channels
4.6K
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...
Sensory...
4.6K
Voltage-gated Ion Channels
8.3K
Voltage-gated ion channels are transmembrane proteins that open and close in response to changes in the membrane potential. They are present on the membranes of all electrically excitable cells such as neurons, heart, and muscle cells.
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several...
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several...
8.3K
Ligand-gated Ion Channels
12.4K
Ligand-gated ion channels are transmembrane proteins with a channel for ions to pass through and a binding site for a ligand. The channel opens only when a ligand attaches to the binding site.
Three Subfamilies of Ligand-gated Ion Channels
Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that...
Three Subfamilies of Ligand-gated Ion Channels
Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that...
12.4K

