{"doi":"10.1101/2025.08.01.668199","title":"Vacuolar Phosphatidylinositol 3,4,5-trisphosphate controls fusion through binding Vam7, and membrane microdomain assembly","abstract":"Abstract Membrane trafficking is regulated by phosphoinositides (PI) and their modification. The endolysosomal pathway is controlled by PI3P, PI(4,5)P 2 and PI(3,5)P 2 , whereas a role for PI(3,4,5)P 3 is less clear. We report that yeast vacuoles produce PI(3,4,5)P 3 through Vps34 activity. In vitro assays showed that dioctanoyl (C8) PI(3,4,5)P 3 or the PI(3,4,5)P 3 -binding domain Grp1-PH blocked fusion. Furthermore, modifying endogenous PI(3,4,5)P 3 with the phosphatase PTEN abolished fusion. Fluorescence microscopy showed that PI(3,4,5)P 3 was present at the plasma membrane and the vertex microdomains of vacuoles. PI(3,4,5)P 3 staining was blocked by PTEN, C8-PI(3,4,5)P 3 , the Vps34 inhibitor SAR405 and a VPS34 temperature sensitive mutation. Importantly, blocking or eliminating PI(3,4,5)P 3 prevented the vertex enrichment of Ypt7 and the HOPS subunit Vps33. Finally, we show that the SNARE Vam7 binds PI(3,4,5)P 3 and that both Grp1-PH and PTEN displaced it from membranes to block trans-SNARE pairing. Our results demonstrate that vacuolar PI(3,4,5)P 3 coordinates vertex assembly and SNARE function.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2025,"id":571553,"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":0.9583,"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":463213,"name":"Jorge D. Calderin","orcid":"0000-0002-9462-6180","position":1,"is_corresponding":false},{"id":1477672,"name":"Aliasgar Topiwalla","orcid":null,"position":2,"is_corresponding":false},{"id":1338323,"name":"Ved Shah","orcid":null,"position":3,"is_corresponding":false},{"id":1338325,"name":"Jahnavi M. Karat","orcid":null,"position":4,"is_corresponding":false},{"id":1338322,"name":"Charlie T. Knapp","orcid":null,"position":5,"is_corresponding":false},{"id":1338321,"name":"Razeen Ahmed","orcid":null,"position":6,"is_corresponding":false},{"id":1338324,"name":"Daniel Grudzien","orcid":null,"position":7,"is_corresponding":false},{"id":170357,"name":"Elizabeth Williamson","orcid":null,"position":8,"is_corresponding":false},{"id":369259,"name":"Rutilio A. Fratti","orcid":"0000-0001-9109-6666","position":9,"is_corresponding":false},{"id":369255,"name":"Chi Zhang","orcid":"0000-0002-7735-5614","position":0,"is_corresponding":true}],"reference_count":104,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-07-19T02:57:15.755535Z","pmid":"40766606","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":[]}