title: Gentamicin inhibits HSP70-assisted protein folding by interfering with substrate recognition.
abstract: We previously reported that gentamicin (GM) specifically binds to heat-shock protein with subunit molecular masses of 70 kDa (HSP70). In the present study, we have investigated the effects of GM binding on HSP70-assisted protein folding in vitro. The C-terminal, and not the N-terminal of HSP70 was found to bind to GM. GM significantly suppressed refolding of firefly luciferase in the presence of HSP70 and HSP40, although the ATPase activity of HSP70 was unaffected by GM. A surface plasmon resonance analysis revealed that GM specifically interferes with the binding of HSP70 to a model peptide that mimics the exposed hydrophobic surface of the folding intermediates. These results indicated that GM inhibits the chaperone activity of HSP70 and may suppress protein folding via inhibition of HSP70 in vivo.
authors.affiliation: Department of Life Science, Faculty of Engineering and Resource Science, Akita University, Akita City, Japan.
authors.forename: Soh
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Nakano
authors.forename: Kensuke
authors.initials: K
authors.lastname: Owari
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Fuziwara
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Ogawa
authors.forename: Michiro
authors.initials: M
authors.lastname: Otaka
authors.forename: Kumiko
authors.initials: K
authors.lastname: Tamaki
authors.forename: Sumio
authors.initials: S
authors.lastname: Watanabe
authors.forename: Atsushi
authors.initials: A
authors.lastname: Komatsuda
authors.forename: Hideki
authors.initials: H
authors.lastname: Wakui
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Sawada
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kubota
authors.forename: Hideaki
authors.initials: H
authors.lastname: Itoh
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000595:Amino Acid Sequence; D001665:Binding Sites; D002846:Chromatography, Affinity; D005839:Gentamicins / Q000737:chemistry / Q000378:metabolism*; D050956:HSP40 Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D049409:Luciferases, Firefly / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding; D017510:Protein Folding; D020349:Surface Plasmon Resonance
chemical_list: D005839:Gentamicins; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D049409:Luciferases, Firefly; D000251:Adenosine Triphosphatases