{"doi":"10.1073/pnas.2024288118","title":"The structure of the native cardiac thin filament at systolic Ca <sup>2+</sup> levels","abstract":"Significance Heartbeats rely on cyclical interactions between myosin thick and actin thin filaments orchestrated by rising and falling Ca 2+ . During systole, Ca 2+ binds to the thin filament and allows its interaction with the thick filament to produce force required for contraction. The structure of the thin filament at physiological Ca 2+ levels is unknown, which limits our understanding of the thin filament regulation by Ca 2+ . Here, we directly observe thin filament structural states along individual filaments at systolic Ca 2+ levels to show that the thin filament is activated stochastically with short-range cooperativity evident only on one strand of the thin filament. We suggest how cardiac muscle can be regulated by a narrow range of Ca 2+ levels upon transition from diastole to systole.","journal":"Proceedings of the National Academy of Sciences","year":2021,"id":151256,"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":84,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9488,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":511055,"name":"Ian Pepper","orcid":null,"position":1,"is_corresponding":false},{"id":642877,"name":"Betty Belknap","orcid":"0000-0002-0935-0336","position":2,"is_corresponding":false},{"id":642878,"name":"Maicon Landim-Vieira","orcid":"0000-0002-6696-8888","position":3,"is_corresponding":false},{"id":469513,"name":"Howard D. White","orcid":"0000-0003-1066-2051","position":4,"is_corresponding":false},{"id":461598,"name":"Kelly A. Dryden","orcid":"0000-0003-1351-1080","position":5,"is_corresponding":false},{"id":328411,"name":"José R. Pinto","orcid":"0000-0001-9092-4976","position":6,"is_corresponding":false},{"id":328408,"name":"P. Bryant Chase","orcid":"0000-0001-9701-561X","position":7,"is_corresponding":false},{"id":642879,"name":"Vitold E. Galkin","orcid":"0000-0003-1138-7565","position":8,"is_corresponding":false},{"id":642876,"name":"Cristina M. Risi","orcid":"0000-0002-3145-2072","position":0,"is_corresponding":true}],"reference_count":46,"raw_metadata":null,"created_at":"2026-07-18T23:43:11.293086Z","pmid":"33753506","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":[]}