{"doi":"10.1101/2025.09.14.675619","title":"Membrane potential and feedback dynamics regulate CatSper-mediated progesterone signaling in human sperm","abstract":"Abstract Activation of the sperm-specific Ca 2+ channel CatSper by progesterone evokes rapid changes in intracellular Ca 2+ in human sperm that are required for fertilization. However, the mechanisms regulating the progesterone-induced Ca 2+ signals have remained elusive. Here, we used quantitative kinetic fluorimetry with fast voltage-sensitive fluorescent indicators to investigate how progesterone affects the membrane potential (V m ) of human sperm. Additionally, we employed the FAST M technique to simultaneously record at millisecond time resolution changes in both V m and intracellular Ca 2+ . We show that progesterone evokes a rapid pulse-like depolarization and repolarization. The depolarization is caused by Ca 2+ influx through CatSper, which pulls V m away from a resting membrane potential (V rest ) of −65 mV set by the sperm-specific K + channel Slo3. We further show that V m - and Ca 2+ -dependent mechanisms limit the CatSper-mediated Ca 2+ influx, thereby promoting repolarization and enabling K + efflux through Slo3 channels to restore V rest . Our findings demonstrate that non-genomic progesterone signaling in human sperm is regulated by negative feedback on CatSper and involves a dynamic interplay between CatSper and Slo3 in controlling V m . We anticipate that our novel kinetic, quantitative V m recording and V m /Ca 2+ -multiplexing techniques will reveal additional molecular mechanisms underlying CatSper-mediated Ca 2+ signaling in human sperm both in health and disease.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2025,"id":575103,"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":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.951,"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":1483101,"name":"Dmitry Fridman","orcid":"0000-0001-9270-5611","position":1,"is_corresponding":false},{"id":1483102,"name":"Cristina Biagioni","orcid":"0000-0002-5495-1202","position":2,"is_corresponding":false},{"id":200516,"name":"Evan Miller","orcid":"0000-0002-6556-7679","position":3,"is_corresponding":false},{"id":481289,"name":"U. Benjamin Kaupp","orcid":"0000-0002-0696-6397","position":4,"is_corresponding":false},{"id":481283,"name":"Christoph Brenker","orcid":"0000-0002-4230-2571","position":5,"is_corresponding":false},{"id":282593,"name":"Timo Strünker","orcid":"0000-0003-0812-1547","position":6,"is_corresponding":false},{"id":1483100,"name":"Michelina Kierzek","orcid":"0000-0002-4785-1545","position":0,"is_corresponding":true}],"reference_count":86,"raw_metadata":null,"created_at":"2026-07-19T02:57:48.486077Z","pmid":"41000689","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":[]}