{"doi":"10.1091/mbc.e13-02-0114","title":"Sit4p/PP6 regulates ER-to-Golgi traffic by controlling the dephosphorylation of COPII coat subunits","abstract":"<jats:p>Traffic from the endoplasmic reticulum (ER) to the Golgi complex is initiated when the activated form of the GTPase Sar1p recruits the Sec23p-Sec24p complex to ER membranes. The Sec23p-Sec24p complex, which forms the inner shell of the COPII coat, sorts cargo into ER-derived vesicles. The coat inner shell recruits the Sec13p-Sec31p complex, leading to coat polymerization and vesicle budding. Recent studies revealed that the Sec23p subunit sequentially interacts with three different binding partners to direct a COPII vesicle to the Golgi. One of these binding partners is the serine/threonine kinase Hrr25p. Hrr25p phosphorylates the COPII coat, driving the membrane-bound pool into the cytosol. The phosphorylated coat cannot rebind to the ER to initiate a new round of vesicle budding unless it is dephosphorylated. Here we screen all known protein phosphatases in yeast to identify one whose loss of function alters the cellular distribution of COPII coat subunits. This screen identifies the PP2A-like phosphatase Sit4p as a regulator of COPII coat dephosphorylation. Hyperphosphorylated coat subunits accumulate in the sit4Δ mutant in vivo. In vitro, Sit4p dephosphorylates COPII coat subunits. Consistent with a role in coat recycling, Sit4p and its mammalian orthologue, PP6, regulate traffic from the ER to the Golgi complex.</jats:p>","journal":"Molecular Biology of the Cell","year":2013,"id":17095,"datarank":1.5533675870578256,"base_score":3.9318256327243257,"endowment":3.9318256327243257,"self_citation_contribution":0.5897738449086489,"citation_network_contribution":0.9635937421491768,"self_endowment_contribution":0.5897738449086489,"citer_contribution":0.9635937421491768,"corpus_percentile":null,"corpus_rank":null,"citation_count":50,"citer_count":46,"citers_with_citation_signal":37,"citers_with_endowment":37,"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":123515,"name":"Jinzhong Zhang","orcid":null,"position":1,"is_corresponding":false},{"id":123516,"name":"Shekar Menon","orcid":null,"position":2,"is_corresponding":false},{"id":123517,"name":"Christopher Lord","orcid":null,"position":3,"is_corresponding":false},{"id":121773,"name":"Shuliang Chen","orcid":"0000-0002-7175-7604","position":4,"is_corresponding":false},{"id":121827,"name":"Jared R. Helm","orcid":null,"position":5,"is_corresponding":false},{"id":123518,"name":"Kevin Thorsen","orcid":null,"position":6,"is_corresponding":false},{"id":106560,"name":"Kevin D. Corbett","orcid":"0000-0001-5854-2388","position":7,"is_corresponding":false},{"id":121831,"name":"Jesse C. Hay","orcid":null,"position":8,"is_corresponding":false},{"id":121778,"name":"Susan Ferro-Novick","orcid":"0000-0001-8714-7352","position":9,"is_corresponding":false},{"id":123514,"name":"Deepali Bhandari","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"base_score":3.9318256327243257,"endowment":3.9318256327243257,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"23864707","pmcid":"PMC3756924","openalex_id":"https://openalex.org/W2153452891","authors":[],"funders":[{"funder_name":"NIGMS NIH HHS","grant_id":"GM106323","title":null},{"funder_name":"NIGMS NIH HHS","grant_id":"R01 GM104141","title":null},{"funder_name":"NIGMS NIH HHS","grant_id":"R15 GM106323","title":null},{"funder_name":"National Institutes of Health","grant_id":"5R01GM104141-10","title":"Molecular mechanisms of chromosome organization and recombination control by the meiotic chromosome axis"},{"funder_name":"National Institutes of Health","grant_id":"1R15GM106323-01","title":"Regulation of ER to Golgi Transport by Luminal Calcium"},{"funder_name":"Howard Hughes Medical Institute","grant_id":"","title":null},{"funder_name":"Howard Hughes Medical Institute","grant_id":"","title":null}],"total_grants":7,"fwci":2.6229,"citation_percentile":0.88998719,"influential_citations":0,"citation_trend":[{"year":2013,"count":1},{"year":2014,"count":4},{"year":2015,"count":6},{"year":2016,"count":5},{"year":2017,"count":3},{"year":2018,"count":5},{"year":2019,"count":3},{"year":2020,"count":4},{"year":2021,"count":6},{"year":2022,"count":2},{"year":2023,"count":4},{"year":2024,"count":2},{"year":2025,"count":5}],"oa_status":"closed","license":"CC BY NC SA","oa_locations":[{"url":"https://doi.org/10.1091/mbc.e13-02-0114","host_type":"HYBRID"},{"url":"https://pubmed.ncbi.nlm.nih.gov/23864707","host_type":"repository"},{"url":"https://escholarship.org/uc/item/5kw246v7","host_type":"repository"},{"url":"https://www.ncbi.nlm.nih.gov/pmc/articles/3756924","host_type":"repository"},{"url":"https://europepmc.org/articles/PMC3756924","host_type":"Europe_PMC"},{"url":"https://europepmc.org/articles/PMC3756924?pdf=render","host_type":"Europe_PMC"},{"url":"http://dx.doi.org/10.1091/mbc.E13-02-0114","host_type":""},{"url":"https://dx.doi.org/10.1091/mbc.e13-02-0114","host_type":""},{"url":"https://doi.org/https://doi.org/10.1091/mbc.e13-02-0114","host_type":""}],"fields_of_study":["Cellular transport and secretion","Endoplasmic Reticulum Stress and Disease","Microtubule and mitosis dynamics","Medicine","Biology","0301 basic medicine","03 medical and health sciences","0303 health sciences","Animals","COP-Coated Vesicles","COS Cells","Chlorocebus aethiops","Endoplasmic Reticulum","Golgi Apparatus","HeLa Cells","Humans","Membrane Proteins","Phosphorylation","Protein Phosphatase 2","Saccharomyces cerevisiae","Saccharomyces cerevisiae Proteins","Vesicular Transport Proteins"],"mesh_terms":["Animals","Chlorocebus aethiops","Endoplasmic Reticulum","Golgi Apparatus","HeLa Cells","Humans","Membrane Proteins","Phosphorylation","Saccharomyces cerevisiae","COS Cells","COP-Coated Vesicles","Saccharomyces cerevisiae Proteins","Vesicular Transport Proteins","Protein Phosphatase 2","Hela Cells"],"keywords":["COPII","Cell biology","COPI","Biology","Endoplasmic reticulum","Golgi apparatus","Dephosphorylation","Vesicle","Protein subunit","Phosphorylation","Secretory pathway","Phosphatase","Biochemistry","Membrane","Saccharomyces cerevisiae Proteins","1.1 Normal biological development and functioning","Vesicular Transport Proteins","Saccharomyces cerevisiae","Medical and Health Sciences","Underpinning research","Chlorocebus aethiops","Animals","Humans","Protein Phosphatase 2","Membrane Proteins","Articles","Biological Sciences","Hela Cells","Biochemistry and cell biology","COS Cells","Generic health relevance","COP-Coated Vesicles","Developmental Biology"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-06-02T16:42:28.737897Z","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":[]}