Related Experiment Video
Updated: Jun 3, 2026

Method for Identifying Small Molecule Inhibitors of the Protein-protein Interaction Between HCN1 and TRIP8b
Published on: November 11, 2016
Tissue-specific N terminus of the HCN4 channel affects channel activation
1Section of Neurobiology, Center for Learning and Memory, University of Texas, Austin, Texas 78712, USA.
Abstract:
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are expressed in the brain and heart and are essential for physiological functions in cardiac and nervous systems. We identified two Hcn4 mRNA variants with different transcription start sites and differential expression patterns in mouse brain and heart. Only one mRNA variant was detected in the brain, whereas both variants were found in the heart. Patch clamp recordings of these two variants in HEK293H cells revealed different electrophysiological properties in channel activation. Mutagenesis studies showed that three positively charged amino acids (Arg-9, Lys-10, and Lys-22) contribute to the functional difference. Our results demonstrate that HCN4 channels are expressed in different patterns in mouse brain and heart and that the N terminus is important for HCN4 channel activation.
More Related Videos
Related Concept Videos
Ligand-Gated Ion Channel Receptor: Gating Mechanism
Ligand-gated Ion Channels
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 include the...
Voltage-gated Ion Channels
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...
Mechanically-gated Ion Channels
Cadherins in Tissue Organization
Cell Sorting During Development
Cell sorting plays an...
The Role of Ion Channels in Neuronal Computation
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.

