{"doi":"10.3390/v13040551","title":"Site-Specific O-Glycosylation Analysis of SARS-CoV-2 Spike Protein Produced in Insect and Human Cells","abstract":"Enveloped viruses hijack not only the host translation processes, but also its glycosylation machinery, and to a variable extent cover viral surface proteins with tolerogenic host-like structures. SARS-CoV-2 surface protein S presents as a trimer on the viral surface and is covered by a dense shield of N-linked glycans, and a few O-glycosites have been reported. The location of O-glycans is controlled by a large family of initiating enzymes with variable expression in cells and tissues and hence is difficult to predict. Here, we used our well-established O-glycoproteomic workflows to map the precise positions of O-linked glycosylation sites on three different entities of protein S-insect cell or human cell-produced ectodomains, or insect cell derived receptor binding domain (RBD). In total 25 O-glycosites were identified, with similar patterns in the two ectodomains of different cell origin, and a distinct pattern of the monomeric RBD. Strikingly, 16 out of 25 O-glycosites were located within three amino acids from known N-glycosites. However, O-glycosylation was primarily found on peptides that were unoccupied by N-glycans, and otherwise had low overall occupancy. This suggests possible complementary functions of O-glycans in immune shielding and negligible effects of O-glycosylation on subunit vaccine design for SARS-CoV-2.","journal":"Viruses","year":2021,"id":151742,"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":80,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9571,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":270519,"name":"Andrew J. Thompson","orcid":"0000-0001-7865-1856","position":1,"is_corresponding":false},{"id":230744,"name":"Xiaoning Wang","orcid":"0000-0003-0153-324X","position":2,"is_corresponding":false},{"id":644813,"name":"Max Søgaard","orcid":"0000-0001-6224-4818","position":3,"is_corresponding":false},{"id":644814,"name":"Cyrielle Fougeroux","orcid":"0000-0002-7566-8377","position":4,"is_corresponding":false},{"id":477459,"name":"Martin Frank","orcid":"0000-0002-1006-6746","position":5,"is_corresponding":false},{"id":90672,"name":"Jolene K. Diedrich","orcid":"0000-0001-6489-4558","position":6,"is_corresponding":false},{"id":55408,"name":"John R. Yates","orcid":"0000-0001-5267-1672","position":7,"is_corresponding":false},{"id":516476,"name":"Ali Salanti","orcid":"0000-0003-2207-5575","position":8,"is_corresponding":false},{"id":628479,"name":"Sergey Y. Vakhrushev","orcid":"0000-0002-0418-5765","position":9,"is_corresponding":false},{"id":230746,"name":"James C. Paulson","orcid":"0000-0003-4589-5322","position":10,"is_corresponding":false},{"id":422431,"name":"Hans H. Wandall","orcid":"0000-0003-0240-9232","position":11,"is_corresponding":false},{"id":347284,"name":"Ieva Bagdonaite","orcid":"0000-0002-9383-8448","position":0,"is_corresponding":true}],"reference_count":37,"raw_metadata":null,"created_at":"2026-07-18T23:43:16.823357Z","pmid":"33806155","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":[]}