{"doi":"10.1091/mbc.9.6.1265","title":"Immunoisolation and Characterization of a Subdomain of the Endoplasmic Reticulum That Concentrates Proteins Involved in COPII Vesicle Biogenesis","abstract":"<jats:p>Rubella virus E1 glycoprotein normally complexes with E2 in the endoplasmic reticulum (ER) to form a heterodimer that is transported to and retained in the Golgi complex. In a previous study, we showed that in the absence of E2, unassembled E1 subunits accumulate in a tubular pre-Golgi compartment whose morphology and biochemical properties are distinct from both rough ER and Golgi. We hypothesized that this compartment corresponds to hypertrophied ER exit sites that have expanded in response to overexpression of E1. In the present study we constructed BHK cells stably expressing E1 protein containing a cytoplasmically disposed epitope and isolated the pre-Golgi compartment from these cells by cell fractionation and immunoisolation. Double label indirect immunofluorescence in cells and immunoblotting of immunoisolated tubular networks revealed that proteins involved in formation of ER-derived transport vesicles, namely p58/ERGIC 53, Sec23p, and Sec13p, were concentrated in the E1-containing pre-Golgi compartment. Furthermore, budding structures were evident in these membrane profiles, and a highly abundant but unknown 65-kDa protein was also present. By comparison, marker proteins of the rough ER, Golgi, and COPI vesicles were not enriched in these membranes. These results demonstrate that the composition of the tubular networks corresponds to that expected of ER exit sites. Accordingly, we propose the name SEREC (smooth ER exit compartment) for this structure.</jats:p>","journal":"Molecular Biology of the Cell","year":1998,"id":20356,"datarank":2.656024847069598,"base_score":3.912023005428146,"endowment":3.912023005428146,"self_citation_contribution":0.586803450814222,"citation_network_contribution":2.069221396255376,"self_endowment_contribution":0.586803450814222,"citer_contribution":2.069221396255376,"corpus_percentile":null,"corpus_rank":null,"citation_count":49,"citer_count":47,"citers_with_citation_signal":43,"citers_with_endowment":43,"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":134843,"name":"Baoping Zhao","orcid":null,"position":1,"is_corresponding":false},{"id":134844,"name":"Honey Chan","orcid":null,"position":2,"is_corresponding":false},{"id":134845,"name":"Marilyn Gist Farquhar","orcid":null,"position":3,"is_corresponding":false},{"id":134842,"name":"Tom C. Hobman","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"base_score":3.912023005428146,"endowment":3.912023005428146,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"9614173","pmcid":null,"openalex_id":"https://openalex.org/W2113776812","authors":[],"funders":[{"funder_name":"NIDDK NIH HHS","grant_id":"R01 DK017780","title":null},{"funder_name":"NIDDK NIH HHS","grant_id":"DK-17780","title":null}],"total_grants":2,"fwci":1.6378,"citation_percentile":0.84210526,"influential_citations":2,"citation_trend":[{"year":2012,"count":1},{"year":2013,"count":2},{"year":2017,"count":1},{"year":2018,"count":2},{"year":2021,"count":1},{"year":2022,"count":1},{"year":2023,"count":3}],"oa_status":"green","license":null,"oa_locations":[{"url":"https://europepmc.org/articles/pmc25349?pdf=render","host_type":"GREEN"},{"url":"https://doi.org/10.1091/mbc.9.6.1265","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/9614173","host_type":"repository"},{"url":"https://www.ncbi.nlm.nih.gov/pmc/articles/25349","host_type":"repository"}],"fields_of_study":["Cellular transport and secretion","Calcium signaling and nucleotide metabolism","Endoplasmic Reticulum Stress and Disease","Biology","Medicine","Animals","Binding Sites","COP-Coated Vesicles","Cell Line","Coated Vesicles","Cricetinae","Endoplasmic Reticulum, Rough","Fungal Proteins","GTPase-Activating Proteins","Golgi Apparatus","Intracellular Membranes","Mannose-Binding Lectins","Membrane Proteins","Mutagenesis","Nuclear Pore Complex Proteins","Saccharomyces cerevisiae Proteins","Transfection","Viral Envelope Proteins"],"mesh_terms":["Animals","Binding Sites","Cell Line","Fungal Proteins","Golgi Apparatus","Cricetinae","Intracellular Membranes","Membrane Proteins","Transfection","Viral Envelope Proteins","Mutagenesis","Coated Vesicles","Endoplasmic Reticulum, Rough","GTPase-Activating Proteins","COP-Coated Vesicles","Nuclear Pore Complex Proteins","Saccharomyces cerevisiae Proteins","Mannose-Binding Lectins"],"keywords":["Golgi apparatus","Endoplasmic reticulum","COPI","COPII","Biology","Cell biology","Vesicle","Biogenesis","Secretory pathway","Compartment (ship)","Cellular compartment","Vesicular Transport Proteins","Secretion","Cell fractionation","Endosome","Transport protein","Brefeldin A","Biochemistry","Cell","Membrane","Vacuolar protein sorting"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-06-04T08:59:41.377601Z","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":[]}