{"doi":"10.1073/pnas.92.20.9303","title":"Reversible phosphorylation controls the activity of cyclosome-associated cyclin-ubiquitin ligase.","abstract":"<jats:p>Cyclin B/cdc2 is responsible both for driving cells into mitosis and for activating the ubiquitin-dependent degradation of mitotic cyclins near the end of mitosis, an event required for the completion of mitosis and entry into interphase of the next cell cycle. Previous work with cell-free extracts of rapidly dividing clam embryos has identified two specific components required for the ubiquitination of mitotic cyclins: E2-C, a cyclin-selective ubiquitin carrier protein that is constitutively active during the cell cycle, and E3-C, a cyclin-selective ubiquitin ligase that purifies as part of a approximately 1500-kDa complex, termed the cyclosome, and which is active only near the end of mitosis. Here, we have separated the cyclosome from its ultimate upstream activator, cdc2. The mitotic, active form of the cyclosome can be inactivated by incubation with a partially purified, endogenous okadaic acid-sensitive phosphatase; addition of cdc2 restores activity to the cyclosome after a lag that reproduces that seen previously in intact cells and in crude extracts. These results demonstrate that activity of cyclin-ubiquitin ligase is controlled by reversible phosphorylation of the cyclosome complex.</jats:p>","journal":"Proceedings of the National Academy of Sciences","year":1995,"id":687619,"datarank":0.7954957362088615,"base_score":5.303304908059076,"endowment":5.303304908059076,"self_citation_contribution":0.7954957362088615,"citation_network_contribution":0.0,"self_endowment_contribution":0.7954957362088615,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":200,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1796382,"name":"V Sudakin","orcid":null,"position":1,"is_corresponding":false},{"id":1599715,"name":"J V Ruderman","orcid":null,"position":2,"is_corresponding":false},{"id":1796383,"name":"A Hershko","orcid":null,"position":3,"is_corresponding":false},{"id":1796381,"name":"S Lahav-Baratz","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"Reversible phosphorylation controls the activity of cyclosome-associated cyclin-ubiquitin ligase.","abstract":"<jats:p>Cyclin B/cdc2 is responsible both for driving cells into mitosis and for activating the ubiquitin-dependent degradation of mitotic cyclins near the end of mitosis, an event required for the completion of mitosis and entry into interphase of the next cell cycle. Previous work with cell-free extracts of rapidly dividing clam embryos has identified two specific components required for the ubiquitination of mitotic cyclins: E2-C, a cyclin-selective ubiquitin carrier protein that is constitutively active during the cell cycle, and E3-C, a cyclin-selective ubiquitin ligase that purifies as part of a approximately 1500-kDa complex, termed the cyclosome, and which is active only near the end of mitosis. Here, we have separated the cyclosome from its ultimate upstream activator, cdc2. The mitotic, active form of the cyclosome can be inactivated by incubation with a partially purified, endogenous okadaic acid-sensitive phosphatase; addition of cdc2 restores activity to the cyclosome after a lag that reproduces that seen previously in intact cells and in crude extracts. These results demonstrate that activity of cyclin-ubiquitin ligase is controlled by reversible phosphorylation of the cyclosome complex.</jats:p>","is_dataset_classified":null,"base_score":5.303304908059076,"endowment":5.303304908059076,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"7568122","pmcid":"PMC40973","openalex_id":"https://openalex.org/W2016274030","authors":[],"funders":[{"funder_name":"NIDDK NIH HHS","grant_id":"DK-25614","title":null},{"funder_name":"NICHD NIH HHS","grant_id":"HD-23696","title":null}],"total_grants":2,"fwci":7.9495,"citation_percentile":0.98256457,"influential_citations":0,"citation_trend":[{"year":2012,"count":1},{"year":2013,"count":5},{"year":2014,"count":2},{"year":2015,"count":1},{"year":2016,"count":2},{"year":2017,"count":4},{"year":2018,"count":3},{"year":2019,"count":1},{"year":2020,"count":3},{"year":2021,"count":5},{"year":2022,"count":3},{"year":2024,"count":5},{"year":2025,"count":1},{"year":2026,"count":2}],"oa_status":"green","license":null,"oa_locations":[{"url":"https://www.ncbi.nlm.nih.gov/pmc/articles/40973","host_type":"repository"},{"url":"https://www.ncbi.nlm.nih.gov/pmc/articles/40973","host_type":"repository"},{"url":"https://pnas.org/doi/pdf/10.1073/pnas.92.20.9303","host_type":"publisher"},{"url":"https://doi.org/10.1073/pnas.92.20.9303","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/7568122","host_type":"repository"}],"fields_of_study":["Ubiquitin and proteasome pathways","Microtubule and mitosis dynamics","14-3-3 protein interactions","Animals","Bivalvia","CDC2 Protein Kinase","Cell Cycle","Cyclins","Embryo, Nonmammalian","Enzyme Inhibitors","Ethers, Cyclic","Female","Kinetics","Ligases","Mitosis","Okadaic Acid","Oocytes","Organelles","Phosphorylation","Protein Tyrosine Phosphatases","Ubiquitin-Protein Ligases"],"mesh_terms":["Animals","Cell Cycle","Embryo, Nonmammalian","Enzyme Inhibitors","Ethers, Cyclic","Female","Kinetics","Ligases","Mitosis","Oocytes","Phosphorylation","Organelles","CDC2 Protein Kinase","Cyclins","Protein Tyrosine Phosphatases","Okadaic Acid","Ubiquitin-Protein Ligases","Bivalvia"],"keywords":["Cyclin B","Ubiquitin ligase","Mitosis","Cyclin B1","Biology","Cyclin-dependent kinase 1","Cyclin A","Mitotic exit","Cell biology","Cell cycle","Cyclin","Biochemistry","Cyclin A2","Cyclin D","Ubiquitin","Molecular biology","Cell","Anaphase"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-18T22:21:42.015505Z","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":[]}