2026-10-09T11:11:55Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34049512 2026-10-01T17:46:55Z category_4 category_12 category_13 category_14 category_15 category_16 category_64 category_128 portal_5 item_type_3 month_year_10_2026

<p>Strains used in this study.</p> Xinyu Huang (679541) Sudharsan Kannan (25158064) Gail A. Robertson (15007385) Han Wang (254423) Biochemistry Cell Biology Genetics Molecular Biology Neuroscience Physiology Cancer Hematology regulate neuronal excitability promoting neuron ala influence channel gating hallmark cyclic nucleotide genetic analysis demonstrated forward genetics reveals electrophysiological analysis showed dependent channel activation calcium imaging showed binding homology domains adjacent channel subunits accelerates activation kinetics subfamily kcnh channels conserved molecular mechanism important sleep regulator findings identify egl div >< p caenorhabditis elegans </ similarly suppresses sleep 2 functions cell elegans </ suppresses sleep kcnh voltage vivo </ central sleep conserved cnbhd shifts voltage second substitution negative potentials intrinsic ligand g574r ), function effects corresponding residue <div><p>KCNH voltage-gated potassium channels regulate neuronal excitability, yet how their hallmark cyclic nucleotide-binding homology domains (CNBHDs) influence channel gating to regulate behavior remains unclear. Using an unbiased forward genetic screen in <i>Caenorhabditis elegans</i>, we identified a gain-of-function mutation in the EAG-subfamily KCNH channel EGL-2 that suppresses sleep. The mutation (G574E) alters a highly conserved glycine residue at the interface between CNBHDs of adjacent channel subunits. EGL-2 functions cell-autonomously in the central sleep-promoting neuron ALA. <i>In vivo</i> calcium imaging showed that the gain-of-function mutation suppresses sleep by inhibiting ALA neuronal activity, consistent with enhanced potassium channel activity. Genetic analysis demonstrated that the sleep-suppressing phenotype of G574E requires both an intact potassium selectivity filter and the intrinsic ligand-occupied CNBHD. A second substitution at the same glycine (G574R), which introduces a positively charged side chain in contrast to the negatively charged side chain in G574E, similarly suppresses sleep, indicating that perturbation of the CNBHD-CNBHD interface, rather than the specific amino acid change, underlies the phenotype. Moreover, mutations at the corresponding residue in the ERG-subfamily KCNH channels <i>C. elegans</i> UNC-103 and human hERG also produce gain-of-function effects, and electrophysiological analysis showed that hERG(G749R) shifts voltage-dependent channel activation to more negative potentials and accelerates activation kinetics. These findings identify EGL-2 as an important sleep regulator and uncover a conserved molecular mechanism by which the CNBHD-CNBHD interface restrains KCNH channel activation to regulate neuronal excitability and behavior.</p></div> 2026-10-01T17:46:48Z Dataset Dataset 10.1371/journal.pgen.1012255.s005 https://figshare.com/articles/dataset/_p_Strains_used_in_this_study_p_/34049512 CC BY 4.0