{"doi":"10.1101/2023.06.20.545672","title":"The increase of Cyclin A/cdk activity and of FAM122A-dependent inhibition of PP2A-B55 are the key events triggering mitosis","abstract":"ABSTRACT Entry into mitosis has been classically attributed to the activation of cyclin B/cdk1 amplification loop by a partial pool of this kinase that becomes active at the end of G2. However, how this pool is activated is still unknown. Here we discovered a new role of the recently identified PP2A-B55 inhibitor FAM122A in triggering mitotic entry. Accordingly, the depletion of the orthologue of FAM122A in C. elegans , prevents entry into mitosis in germline stem cells. Moreover, our data in Xenopus egg extract strongly supports that FAM122A-dependent inhibition of PP2A-B55 could be the initial event promoting mitotic entry. The inhibition of this phosphatase allows the subsequent phosphorylation of first mitotic substrates by cyclin A/cdk resulting in cyclin B/cdk1 and Greatwall (Gwl) activation. However, interestingly, from Gwl activation, Arpp19/ENSA become phosphorylated and compete with FAM122A promoting its dissociation from PP2A-B55 and taking over its inhibition until the end of mitosis.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2023,"id":408887,"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":0.951,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2023-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1188720,"name":"Suzanne Vigneron","orcid":null,"position":1,"is_corresponding":false},{"id":532639,"name":"Jean Claude Labbé","orcid":null,"position":2,"is_corresponding":false},{"id":375690,"name":"Lionel Pintard","orcid":"0000-0003-0286-4630","position":3,"is_corresponding":false},{"id":818890,"name":"Gilles Labesse","orcid":"0000-0002-6861-3300","position":4,"is_corresponding":false},{"id":1188421,"name":"Anna Castro","orcid":"0000-0002-3655-1352","position":5,"is_corresponding":false},{"id":1188422,"name":"Thierry Lorca","orcid":"0000-0003-2007-8924","position":6,"is_corresponding":false},{"id":590556,"name":"Benjamin Lacroix","orcid":"0000-0003-2533-9150","position":0,"is_corresponding":true}],"reference_count":30,"raw_metadata":null,"created_at":"2026-07-19T01:21:22.368387Z","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":[]}