{"doi":"10.1016/j.bpj.2025.06.029","title":"Voltage gating and 4-aminopyridine inhibition in the Shaker Kv channel revealed by a closed-state model","abstract":"The generation and propagation of action potentials in neurons relies on the coordinated activation of voltage-dependent sodium and potassium channels. The Kv1 (Shaker) family of potassium channels drives the repolarization phase of the action potential by opening and closing their pore, a process controlled by a voltage sensor domain. However, a molecular description of how the voltage sensor domain drives pore gating has been constrained by a lack of closed-state structures. Here, we present a structural model of the closed Shaker channel that reveals the structural basis of voltage gating. Using AlphaFold2-based conformational sampling, we identified a partially activated state of the voltage sensor which, when modeled with the full channel, produced a closed state. Based on this model we demonstrate that breaking a backbone hydrogen bond between the S4-S5 linker and S5 helices is a critical part of the activation pathway. Docking studies revealed a hydrophobic cavity in the closed pore that binds 4-aminopyridine, a potassium channel inhibitor used to enhance nerve conduction in multiple sclerosis. Our results demonstrate how the voltage sensor movement drives pore opening and provide a structural framework for developing new therapeutic agents targeting the closed state. We anticipate that the novel methods used in this work will allow the characterization of conformational dynamics in voltage-gated ion channels, enabling drug design efforts focused on state-dependent modulation of ion channels for neurological disorders treatment.","journal":"Biophysical Journal","year":2025,"id":541565,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":2,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.952,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":887323,"name":"Bernardo I. Pinto","orcid":"0000-0003-0200-1069","position":0,"is_corresponding":true}],"reference_count":63,"raw_metadata":null,"created_at":"2026-07-19T02:52:47.161928Z","pmid":"40566678","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}