{"doi":"10.1101/2020.04.27.063628","title":"<i>Toxoplasma</i> FER1 is a versatile and dynamic mediator of differential microneme trafficking and microneme exocytosis","abstract":"Abstract Toxoplasma gondii is a polarized cell concentrating several secretory organelles at the apical pole. The secretory micronemes come in two sub-populations differentiated by dependence on the Rab5A/C in their biogenesis. Calcium-dependent exocytosis of micronemes occurs at the very apical tip and is critical for parasite egress from its host cell, adhesion and invasion of the next cell. Ferlins represent a protein family with roles in exocytosis containing multiple Ca 2+ -sensing C2 domains. We determined that T. gondii ’s ferlin 1 (FER1) localized dynamically to the parasite’s secretory pathway. FER1 function was dissected by dominant negative overexpression strategies. We demonstrated that FER1 traffics microneme organelles along the following trajectories:1. From the trans -Golgi-endosomes network to the subpellicular cortex; 2. Along the cortex to the apical end; 3. To the apical tip for fusion with the plasma membrane; 4. Retrograde transport allowing microneme recycling from mother to daughter; 5. Differential microneme sub-population traffic. Finally, FER1 overexpression triggers a microneme exocytosis burst, supporting the notion that the radially organized micronemes at the apical tip comprise a readily-releasable microneme pool. In summary, FER1 is pivotal for dynamic microneme trafficking, acts differently on the two microneme subpopulations, and acts on the plasma membrane fusion step during microneme exocytosis.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2020,"id":120889,"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":8,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9563,"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":559946,"name":"Adeline Ribeiro E Silva","orcid":null,"position":1,"is_corresponding":false},{"id":559238,"name":"Allison A. Drozda","orcid":"0000-0003-2643-2269","position":2,"is_corresponding":false},{"id":353145,"name":"Isabelle Coppens","orcid":"0000-0001-5549-2362","position":3,"is_corresponding":false},{"id":559239,"name":"Bradley I. Coleman","orcid":"0000-0003-4217-508X","position":4,"is_corresponding":false},{"id":559240,"name":"Marc‐Jan Gubbels","orcid":"0000-0002-2769-8600","position":5,"is_corresponding":false},{"id":559237,"name":"Daniel N. A. Tagoe","orcid":"0000-0001-6268-7838","position":0,"is_corresponding":true}],"reference_count":136,"raw_metadata":null,"created_at":"2026-07-18T23:14:38.147936Z","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":[]}