{"doi":"10.17615/83yv-nm15","title":"4-Alkyloxyimino-cytosine nucleotides: tethering approaches to molecular probes for the P2Y6 receptor","abstract":"4-Alkyloxyimino derivatives of pyrimidine nucleotides display high potency as agonists of certain G protein-coupled P2Y receptors (P2YRs). In an effort to functionalize a P2Y6R agonist for fluorescent labeling, we probed two positions (N4 and γ-phosphate of cytidine derivatives) with various functional groups, including alkynes for click chemistry. Functionalization of extended imino substituents at the 4 position of the pyrimidine nucleobase of CDP preserved P2Y6R potency generally better than γ-phosphoester formation in CTP derivatives. Fluorescent Alexa Fluor 488 conjugate 16 activated the human P2Y6R expressed in 1321N1 human astrocytoma cells with an EC50 of 9 nM, and exhibited high selectivity for this receptor over other uridine nucleotide-activated P2Y receptors. Flow cytometry detected specific labeling with 16 to P2Y6R-expressing but not to wild-type 1321N1 cells. Additionally, confocal microscopy indicated both internalized 16 (t1/2 of 18 min) and surface-bound fluorescence. Known P2Y6R ligands inhibited labeling. Theoretical docking of 16 to a homology model of the P2Y6R predicted electrostatic interactions between the fluorophore and extracellular portion of TM3. Thus, we have identified the N4-benzyloxy group as a structurally permissive site for synthesis of functionalized congeners leading to high affinity molecular probes for studying the P2Y6R.","journal":"UNC Libraries","year":2021,"id":230964,"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":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9543,"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":256464,"name":"Kyle A. Brown","orcid":"0000-0003-1255-9146","position":1,"is_corresponding":false},{"id":837242,"name":"Eszter Kozma","orcid":"0009-0009-2447-7683","position":2,"is_corresponding":false},{"id":837243,"name":"Lucia Squarcialupi","orcid":"0000-0003-0578-2104","position":3,"is_corresponding":false},{"id":837932,"name":"P. Suresh Jayasekara","orcid":null,"position":4,"is_corresponding":false},{"id":547602,"name":"Hiroshi Maruoka","orcid":null,"position":5,"is_corresponding":false},{"id":546799,"name":"Matthew O. Barrett","orcid":"0000-0001-7851-0308","position":6,"is_corresponding":false},{"id":515149,"name":"Stefano Costanzi","orcid":"0000-0003-3183-7332","position":7,"is_corresponding":false},{"id":233845,"name":"Kenneth A. Jacobson","orcid":"0000-0001-8104-1493","position":8,"is_corresponding":false},{"id":607017,"name":"Рамачандран Баласубраманиан","orcid":"0000-0002-6345-0127","position":9,"is_corresponding":false},{"id":600906,"name":"Christopher B. Ball","orcid":"0000-0002-5983-1605","position":0,"is_corresponding":true}],"reference_count":0,"raw_metadata":null,"created_at":"2026-07-18T23:55:09.211909Z","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":[]}