{"doi":"10.1111/febs.16291","title":"Naturally occurring UBIAD1 mutations differentially affect menaquinone biosynthesis and vitamin K‐dependent carboxylation","abstract":"UbiA prenyltransferase domain-containing protein-1 (UBIAD1) is responsible for the biosynthesis of menaquinone-4 (MK-4), a cofactor for extrahepatic carboxylation of vitamin K-dependent (VKD) proteins. Genetic variations of UBIAD1 are mainly associated with Schnyder corneal dystrophy (SCD), a disease characterized by abnormal accumulation of cholesterol in the cornea. Results from in vitro studies demonstrate that SCD-associated UBIAD1 mutations are defective in MK-4 biosynthesis. However, SCD patients do not exhibit typical phenotypes associated with defects of MK-4 or VKD carboxylation. Here, we coupled UBIAD1's biosynthetic activity of MK-4 with VKD carboxylation in HEK293 cells that stably express a chimeric VKD reporter protein. The endogenous Ubiad1 gene in these cells was knocked out by CRISPR-Cas9-mediated genome editing. The effect of UBIAD1 mutations on MK-4 biosynthesis and VKD carboxylation was evaluated in Ubiad1-deficient reporter cells by determining the production of MK-4 or by measuring the efficiency of reporter-protein carboxylation. Our results show that the hot-spot mutation N102S has a moderate impact on MK-4 biosynthesis (retained ˜ 82% activity) but does not affect VKD carboxylation. However, the G186R mutation significantly affected both MK-4 biosynthesis and VKD carboxylation. Other mutations exhibit varying degrees of effects on MK-4 biosynthesis and VKD carboxylation. These results are consistent with in vivo results obtained from gene knock-in mice and SCD patients. Our findings suggest that UBIAD1's MK-4 biosynthetic activity does not directly correlate with the phenotypes of SCD patients. The established cell-based assays in this study provide a powerful tool for the functional studies of UBIAD1 in a cellular milieu.","journal":"FEBS Journal","year":2021,"id":201855,"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":7,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9586,"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":781949,"name":"Natsuko Furukawa","orcid":null,"position":1,"is_corresponding":false},{"id":387570,"name":"Da‐Yun Jin","orcid":"0000-0002-5148-4899","position":2,"is_corresponding":false},{"id":781312,"name":"Yizhou Liu","orcid":"0000-0001-7456-4069","position":3,"is_corresponding":false},{"id":387578,"name":"Darrel W. Stafford","orcid":"0000-0001-6830-3874","position":4,"is_corresponding":false},{"id":781313,"name":"Craig M. Williams","orcid":"0000-0002-3834-7398","position":5,"is_corresponding":false},{"id":781314,"name":"Yoshitomo Suhara","orcid":"0000-0002-4770-2910","position":6,"is_corresponding":false},{"id":387581,"name":"Jian‐Ke Tie","orcid":"0000-0002-8447-3408","position":7,"is_corresponding":false},{"id":15563,"name":"Xuejie Chen","orcid":"0000-0001-8459-2557","position":0,"is_corresponding":true}],"reference_count":70,"raw_metadata":null,"created_at":"2026-07-18T23:51:05.955461Z","pmid":"34813684","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":[]}