title: Synthetic Ubiquinones Specifically Bind to Mitochondrial Voltage-Dependent Anion Channel 1 (VDAC1) in Saccharomyces cerevisiae Mitochondria.
abstract: The role of the voltage-dependent anion channel (VDAC) as a metabolic gate of the mitochondrial outer membrane has been firmly established; however, its involvement in the regulation of mitochondrial permeability transition (PT) remains extremely controversial. Although some low-molecular-weight chemicals have been proposed to modulate the regulatory role of VDAC in the induction of PT, direct binding between these chemicals and VDAC has not yet been demonstrated. In the present study, we investigated whether the ubiquinone molecule directly binds to VDAC in Saccharomyces cerevisiae mitochondria through a photoaffinity labeling technique using two photoreactive ubiquinones (PUQ-1 and PUQ-2). The results of the labeling experiments demonstrated that PUQ-1 and PUQ-2 specifically bind to VDAC1 and that the labeled position is located in the C-terminal region Phe221-Lys234, connecting the 15th and 16th β-strand sheets. Mutations introduced in this region (R224A, Y225A, D228A, and Y225A/D228A) hardly affected the binding affinity of PUQ-1. PUQ-1 and PUQ-2 both significantly suppressed the Ca2+-induced mitochondrial PT (monitored by mitochondrial swelling) at the one digit μM level. Thus, the results of the present study provided, for the first time to our knowledge, direct evidence indicating that the ubiquinone molecule specifically binds to VDAC1 through its quinone-head ring.
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University , Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Masatoshi
authors.identifier: 0000-0001-6601-2854
authors.initials: M
authors.lastname: Murai
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University , Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Ayaka
authors.initials: A
authors.lastname: Okuda
authors.affiliation: Institute for Genome Research, University of Tokushima , Kuramotocho-3, Tokushima 770-8503, Japan.
authors.forename: Takenori
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Institute for Genome Research, University of Tokushima , Kuramotocho-3, Tokushima 770-8503, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Shinohara
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University , Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Hideto
authors.initials: H
authors.lastname: Miyoshi
mesh_terms: D002118:Calcium / Q000378:metabolism; D015870:Gene Expression; D017136:Ion Transport / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D033681:Mitochondrial Membrane Transport Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D051336:Mitochondrial Membranes / Q000187:drug effects* / Q000378:metabolism; D000083162:Mitochondrial Permeability Transition Pore; D008933:Mitochondrial Swelling / Q000187:drug effects; D008958:Models, Molecular; D009154:Mutation; D010085:Oxidative Phosphorylation / Q000187:drug effects; D011485:Protein Binding; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D013194:Staining and Labeling / Q000379:methods; D014451:Ubiquinone / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000494:pharmacology*; D050995:Voltage-Dependent Anion Channel 1 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D014451:Ubiquinone; D050995:Voltage-Dependent Anion Channel 1; D002118:Calcium