Related Experiment Video
Updated: Mar 9, 2026

08:44
Dynamic Clamp Methods to Investigate Impaired Neuronal Excitability Associated with Autism
Published on: October 17, 2025
772
A reduced mechanical model for cAMP-modulated gating in HCN channels
Stephanie Weißgraeber1, Andrea Saponaro2, Gerhard Thiel1
1Department of Biology, TU Darmstadt, Germany.
Scientific Reports
|January 12, 2017
Summary
We modeled cyclic nucleotide-gated (HCN) channels, revealing a quaternary twist in their cytosolic regions. This motion explains how cAMP binding allosterically modulates channel gating in heart and brain cells.
Area of Science:
- Biophysics
- Molecular Biology
- Computational Biology
Background:
- Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are crucial for regulating cardiac and neuronal electrical activity.
- Cyclic adenosine monophosphate (cAMP) allosterically modulates HCN channel function, impacting cellular excitability.
- Understanding the molecular mechanisms of cAMP-mediated gating is essential for deciphering channelopathies.
Purpose of the Study:
- To develop an in silico mechanical model to investigate cAMP-induced conformational changes in HCN channels.
- To elucidate the structural basis for cAMP's allosteric modulation of HCN channel gating.
Main Methods:
- Development of a computational mechanical model.
- In silico structural analysis of HCN channel tetramers.
- Analysis of conformational differences between cAMP-bound and unbound states.
Main Results:
- Identified a quaternary twist in the cytosolic domains of the HCN channel tetramer upon cAMP binding.
- Revealed augmented intrinsic protein dynamics due to this twisting motion.
- Discovered a key interaction between the cyclic nucleotide binding domain (CNBD) C-linker and the S4-S5 transmembrane linker.
Conclusions:
- The quaternary twist is a key mechanistic feature of cAMP-induced allosteric modulation in HCN channels.
- This motion provides a mechanistic link between cAMP binding and voltage-dependent gating.
- The findings offer insights into the regulation of cardiac and neuronal excitability by HCN channels.
Related Concept Videos
Mechanically-gated Ion Channels
8.0K
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...
8.0K
Ligand-Gated Ion Channel Receptor: Gating Mechanism
4.5K
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...
4.5K
Ligand-gated Ion Channels
14.8K
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...
14.8K
G-Protein Gated Ion Channels
6.5K
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...
6.5K
Non-gated Ion Channels
8.5K
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....
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism....
8.5K
Voltage-gated Ion Channels
12.1K
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 types of...
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 types of...
12.1K

