title: Identification of Targets of the HIF-1 Inhibitor IDF-11774 Using Alkyne-Conjugated Photoaffinity Probes.
abstract: We developed a hypoxia-inducible factor-1 (HIF-1) inhibitor, IDF-11774, as a clinical candidate for cancer therapy. To understand the mechanism of action of IDF-11774, we attempted to isolate target proteins of IDF-11774 using bioconjugated probes. Multifunctional chemical probes containing sites for click conjugation and photoaffinity labeling were designed and synthesized. After fluorescence and photoaffinity labeling of proteins, two-dimensional electrophoresis (2DE) was performed to isolate specific molecular targets of IDF-11774. Heat shock protein (HSP) 70 was identified as a target protein of IDF-11774. We revealed that IDF-11774 inhibited HSP70 chaperone activity by binding to its allosteric pocket, rather than the ATP-binding site in its nucleotide-binding domain (NBD). Moreover, IDF-11774 reduced the oxygen consumption rate (OCR) and ATP production, thereby increasing intracellular oxygen tension. This result suggests that the inhibition of HSP70 chaperone activity by IDF-11774 suppresses HIF-1α refolding and stimulates HIF-1α degradation. Taken together, these findings indicate that IDF-11774-derived chemical probes successfully identified IDF-11774's target molecule, HSP70, and elucidated the mode of action of IDF-11774 in inhibiting HSP70 chaperone activity and stimulating HIF-1α degradation in cancer cells.
authors.forename: Hyun Seung
authors.initials: HS
authors.lastname: Ban
authors.affiliation: College of Pharmacy, Dongguk University-Seoul , Goyang 410-820, Korea.
authors.forename: Ravi
authors.initials: R
authors.lastname: Naik
authors.affiliation: Gachon University , College of Pharmacy, Incheon 406-840, Korea.
authors.forename: Hwan Mook
authors.initials: HM
authors.lastname: Kim
authors.forename: Bo-Kyung
authors.initials: BK
authors.lastname: Kim
authors.affiliation: ILDONG Pharmaceutical Co. Ltd. , Hwaseong, Kyungi-do 445-811, Korea.
authors.forename: Hongsub
authors.initials: H
authors.lastname: Lee
authors.forename: Inhyub
authors.initials: I
authors.lastname: Kim
authors.affiliation: College of Pharmacy, Dongguk University-Seoul , Goyang 410-820, Korea.
authors.forename: Heechul
authors.initials: H
authors.lastname: Ahn
authors.affiliation: College of Pharmacy, Dongguk University-Seoul , Goyang 410-820, Korea.
authors.forename: Yerin
authors.initials: Y
authors.lastname: Jang
authors.affiliation: College of Pharmacy, Dongguk University-Seoul , Goyang 410-820, Korea.
authors.forename: Kyusik
authors.initials: K
authors.lastname: Jang
authors.affiliation: College of Pharmacy, Dongguk University-Seoul , Goyang 410-820, Korea.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Eo
authors.affiliation: Department of Food Science and Technology, Chungnam National University , Daejeon 305-764, Korea.
authors.forename: Kyung Bin
authors.initials: KB
authors.lastname: Song
authors.affiliation: College of Pharmacy, Dongguk University-Seoul , Goyang 410-820, Korea.
authors.forename: Kyeong
authors.initials: K
authors.lastname: Lee
authors.forename: Misun
authors.initials: M
authors.lastname: Won
mesh_terms: D000218:Adamantane / Q000031:analogs & derivatives* / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000480:Alkynes / Q000737:chemistry*; D000495:Allosteric Site / Q000187:drug effects; D019817:Benzoic Acid / Q000494:pharmacology*; D019069:Cell Respiration / Q000187:drug effects; D045325:HCT116 Cells; D018840:HSP70 Heat-Shock Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D051793:Hypoxia-Inducible Factor 1 / Q000037:antagonists & inhibitors*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D008958:Models, Molecular; D010879:Piperazines / Q000494:pharmacology*; D011487:Protein Conformation; D000072417:Protein Domains; D013194:Staining and Labeling
chemical_list: D000480:Alkynes; D018840:HSP70 Heat-Shock Proteins; D051793:Hypoxia-Inducible Factor 1; C000620496:IDF-11774; D010879:Piperazines; D000255:Adenosine Triphosphate; D019817:Benzoic Acid; D000218:Adamantane