{"doi":"10.1101/2025.02.14.638303","title":"The sperm specific Na <sup>+</sup> ,K <sup>+</sup> -ATPase α4 shows a highly structured and dynamic distribution at the sperm flagellum","abstract":"Abstract Na + ,K + -ATPase α4 is a unique cell plasma membrane Na + and K + transporter of spermatozoa, which is essential for male fertility. Previous studies have shown that Na + ,K + -ATPase α4 is highly expressed in the sperm flagellum; however, the spatial arrangement of Na + ,K + -ATPase α4 at the subcellular level and its relationship to the functional state of the cells are unknown. We studied this here using stimulated emission depletion (STED) super-resolution microscopy. We show that, under non-capacitated conditions, Na + ,K + -ATPase α4 is distributed in a trilinear pattern along the midpiece and as a scattered single line along the principal piece segment of the sperm flagellum. Under capacitated conditions, Na + ,K + -ATPase α4 pattern undergoes remodelling and its distribution shifts into a single line along the entire length of the flagellum. On the other hand, Na + ,K + -ATPase α1 the somatic isoform of Na + ,K + -ATPase also present in sperm, exhibits a similar trilaminar localization at the flagellar midpiece but a bilinear pattern in the principal piece. This distribution, unlike that of Na + ,K + -ATPase α4, does not change during sperm capacitation. These differences in the localization pattern and spatial dynamics of Na + ,K + - ATPase isoform expression highlights the dissimilarities in the roles of both ion transporters. The specific modulation of Na + ,K + -ATPase α4 distribution, combined with the unique role that it has in sperm function, stresses the importance of Na + ,K + -ATPase α4 for male fertility. Significance statement This is the first demonstration of the highly structured nature of Na + ,K + -ATPase in the plasma membrane of sperm, including the sperm specific Na + ,K + -ATPase α4 isoform, which is key for male fertility, and the somatic Na + ,K + -ATPase α1, which is present in all cells. Utilizing stimulated emission depletion (STED) super resolution microscopy, we discovered that Na + ,K + - ATPase α4 and Na + ,K + -ATPase α1 have different distributions along the sperm flagellum. Moreover, only Na + ,K + -ATPase α4 undergoes remodelling during sperm capacitation. These specific patterns of localization that are dependent on the sperm functional state in combination with the different function and regulation of Na + ,K + -ATPase isoforms highlights the sophisticated mechanisms that cells have evolved to fulfil their unique function.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2025,"id":557334,"datarank":0.10397207708399181,"base_score":0.6931471805599453,"endowment":0.6931471805599453,"self_citation_contribution":0.10397207708399181,"citation_network_contribution":0.0,"self_endowment_contribution":0.10397207708399181,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9565,"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":1269364,"name":"Jeffrey P. McDermott","orcid":"0000-0002-3566-3483","position":1,"is_corresponding":false},{"id":731606,"name":"Gladis Sánchez","orcid":"0000-0003-1023-7290","position":2,"is_corresponding":false},{"id":731605,"name":"Gustavo Blanco","orcid":"0000-0001-7721-9869","position":3,"is_corresponding":false},{"id":1293950,"name":"Mumtarin Jannat Oishee","orcid":"0000-0001-5101-9930","position":0,"is_corresponding":true}],"reference_count":53,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-07-19T02:55:17.435961Z","pmid":"39990339","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":[]}