KCNH channels are expressed across a vast phylogenetic and evolutionary spectrum. In humans, they function in a wide range of tissues and serve as biomarkers and targets for diseases such as cancer and cardiac arrhythmias. These channels share a general architecture with other voltage-gated ion channels but are distinguished by the presence of an N-terminal PAS (Per-Arnt-Sim) domain and a C-terminal domain with homology to cyclic nucleotide binding domains (referred to as the CNBh domain). Cytosolic regions outside these domains show little conservation between KCNH families but are strongly conserved across species within a family, likely reflecting variability that confers specificity to individual channel types. PAS and CNBh domains participate in channel gating, but at least twice in evolutionary history, the PAS domain has been lost and it is omitted by alternate transcription to create a distinct channel subunit in one family. In this focused review, we present current knowledge of the structure and function of these cytosolic regions, discuss their evolution as modular domains and provide our perspective on the important questions moving forward.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4277939PMC
http://dx.doi.org/10.1016/j.jmb.2014.08.008DOI Listing

Publication Analysis

Top Keywords

kcnh channels
8
cytosolic regions
8
enigmatic cytoplasmic
4
cytoplasmic regions
4
regions kcnh
4
channels
4
channels kcnh
4
channels expressed
4
expressed vast
4
vast phylogenetic
4

Similar Publications

The family of potassium channels serves relevant physiological functions in both excitable and non-excitable cells, reflected in the massive consequences of mutations or pharmacological manipulation of their function. This group of channels shares structural homology with other voltage-gated K channels, but the mechanisms of gating in this family show significant differences with respect to the canonical electromechanical coupling in these molecules. In particular, the large intracellular domains of channels play a crucial role in gating that is still only partly understood.

View Article and Find Full Text PDF

Ion channels are transmembrane proteins essential for cellular functions and are important drug targets. Surface plasmon resonance (SPR) is a powerful technique for investigating protein-protein and protein-small molecule ligand interactions. SPR has been underutilized for studies of ion channels, even though it could provide a wealth of information on the mechanisms of ion channel regulation and aid in ion channel drug discovery.

View Article and Find Full Text PDF

Corydaline binds to a druggable pocket of hEAG1 channel and inhibits hepatic carcinoma cell viability.

Eur J Pharmacol

January 2024

State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin, 300401, China; Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin, 300401, China; Key Laboratory of Molecular Biophysics, Hebei Province, China; Institute of Biophysics, School of Health Sciences and Biomedical Engineering, Hebei University of Technology, Tianjin, 300401, China. Electronic address:

Ether-à-go-go (EAG) potassium channels play a crucial role in the regulation of neuronal excitability and cancer progression, rendering them potential drug targets for cancer therapy. However, the scarcity of information regarding the selection sites on hEAG1 has posed a challenge in the discovery of new hEAG1 inhibitors. In this study, we introduced a novel natural product, corydaline, which selectively inhibits the hEAG1 channel without sensitivity to other KCNH channels.

View Article and Find Full Text PDF

Zebrafish cardiac repolarization does not functionally depend on the expression of the hERG1b-like transcript.

Pflugers Arch

January 2024

Department of Biomedical Physiology and Kinesiology, Simon Fraser University, 8888 University Drive, Burnaby, V5A 1S6, Burnaby, B.C, Canada.

Article Synopsis
  • Zebrafish serve as a useful model for human heart function and can help study heart disorders and medications, but their cardiac repolarization mechanisms differ slightly from humans due to the absence of a functional hERG1b gene.
  • The research identified that zkcnh6a in zebrafish is similar to human hERG1a, but there is also a variant, zkcnh6b, which showed no functional role in the heart's electrical activity.
  • These findings emphasize the importance of recognizing species differences when using zebrafish to study human cardiac repolarization, especially since they lack the hERG1b gene that plays a significant role in human cardiac function and drug interactions.
View Article and Find Full Text PDF

"Short" also matters.

Heart Rhythm

August 2023

Division of Cardiology, Section of Electrophysiology, University of California San Francisco, San Francisco, California. Electronic address:

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!