{"doi":"10.1101/2020.02.17.953331","title":"Sphingolipids regulate the tethering stage of vacuole fusion by affecting membrane fluidity","abstract":"Abstract Sphingolipids are essential in membrane trafficking and cellular homeostasis. Here, we show that sphingolipids containing very long-chain fatty acids (VLCFAs) promote robust homotypic vacuolar fusion in Saccharomyces cerevisiae . The elongase Elo3 adds two carbons to 24-carbon (C24) acyl chains to make C26 VLCFAs that are incorporated into sphingolipids. Vacuoles isolated from elo3 Δ cells had increased fluidity relative to the wild-type and were attenuated for fusion. Upon further testing we found that vesicle the tethering stage was affected as elo3 Δ vacuole clusters contained fewer vesicles versus the WT. Vacuole tethering requires the interactions of late endosomal Rab GTPase Ypt7 and the HOPS tethering complex. Pulldown assays using GST-Ypt7 showed that HOPS from elo3 Δ vacuole extracts failed to bind Ypt7 while HOPS from WT extracts interacted with GST-Ypt7. Furthermore GFP-Ypt7 failed to localize at vertex microdomains of elo3 Δ vacuoles relative to the WT, whereas HOPS and regulatory lipids did accumulate at vertices. Finally, we found that elo3 Δ vacuoles had reduced V-ATPase. Together these data show that C26-VLCFA containing sphingolipids are important for Ytp7 function and vacuole homeostasis.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2020,"id":122589,"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":4,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9618,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":370374,"name":"Logan R. Hurst","orcid":null,"position":1,"is_corresponding":false},{"id":565199,"name":"Zeynep Derin Gokbayrak","orcid":null,"position":2,"is_corresponding":false},{"id":463213,"name":"Jorge D. Calderin","orcid":"0000-0002-9462-6180","position":3,"is_corresponding":false},{"id":565200,"name":"Michael R. Hrabak","orcid":null,"position":4,"is_corresponding":false},{"id":565201,"name":"Adam Balutowski","orcid":null,"position":5,"is_corresponding":false},{"id":369256,"name":"David A. Rivera‐Kohr","orcid":"0000-0001-7199-3490","position":6,"is_corresponding":false},{"id":564264,"name":"Thomas David Daniel Kazmirchuk","orcid":"0000-0003-2962-6819","position":7,"is_corresponding":false},{"id":564265,"name":"Christopher L. Brett","orcid":"0000-0002-0730-3405","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":189,"raw_metadata":null,"created_at":"2026-07-18T23:14:55.385653Z","pmid":null,"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":[]}