title: Hsp90 Oligomers Interacting with the Aha1 Cochaperone: An Outlook for the Hsp90 Chaperone Machineries.
abstract: The 90-kDa heat shock protein (Hsp90) is a highly flexible dimer able to self-associate in the presence of divalent cations or under heat shock. This study investigated the relationship between Hsp90 oligomers and the Hsp90 cochaperone Aha1 (activator of Hsp90 ATPase). The interactions of Aha1 with Hsp90 dimers and oligomers were evaluated by ultracentrifugation, size-exclusion chromatography coupled to multiangle laser light scattering and high-mass matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Hsp90 dimer was able to bind up to four Aha1 molecules, and Hsp90 oligomers are also able to interact with Aha1. The binding of Aha1 did not interfere with the Hsp90 oligomerization process. Except for Hsp90 dimer, the stoichiometry of the interaction remained constant, at 2 Aha1 molecules per Hsp90 dimer, regardless of the degree of Hsp90 oligomerization. Moreover, Aha1 predominantly bound to Hsp90 oligomers. Thus, the ability of Hsp90 oligomers to bind the Aha1 ATPase activator reinforces their role within the Hsp90 chaperone machineries.
authors.affiliation: †Translation and Folding, UMR-CNRS 6290, Université de Rennes 1, Campus Beaulieu, 263 Avenue du Général Leclerc, 35042 Rennes, Cedex, France.
authors.forename: Eléonore
authors.initials: E
authors.lastname: Lepvrier
authors.affiliation: †Translation and Folding, UMR-CNRS 6290, Université de Rennes 1, Campus Beaulieu, 263 Avenue du Général Leclerc, 35042 Rennes, Cedex, France.
authors.forename: Laura
authors.initials: L
authors.lastname: Moullintraffort
authors.affiliation: ‡UMR1208 Ingénierie des Agropolymères et Technologies Emergentes INRA-Montpellier SupAgro-CIRAD, Université Montpellier, 2 Place Pierre Viala, F-34060 Montpellier, France.
authors.forename: Michaël
authors.initials: M
authors.lastname: Nigen
authors.affiliation: §Microbiologie risques infectieux, EA 1254, Université de Rennes 1, Campus Beaulieu, 35042 Rennes, Cedex, France.
authors.forename: Renan
authors.initials: R
authors.lastname: Goude
authors.affiliation: ∥Aix-Marseille Université, INSERM UMR 911, Centre de Recherche en Oncologie biologique et Onco-pharmacologie, 13385 Marseille, Cedex 5, France.
authors.forename: Diane
authors.initials: D
authors.lastname: Allegro
authors.affiliation: ∥Aix-Marseille Université, INSERM UMR 911, Centre de Recherche en Oncologie biologique et Onco-pharmacologie, 13385 Marseille, Cedex 5, France.
authors.forename: Pascale
authors.initials: P
authors.lastname: Barbier
authors.affiliation: ∥Aix-Marseille Université, INSERM UMR 911, Centre de Recherche en Oncologie biologique et Onco-pharmacologie, 13385 Marseille, Cedex 5, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Peyrot
authors.affiliation: †Translation and Folding, UMR-CNRS 6290, Université de Rennes 1, Campus Beaulieu, 263 Avenue du Général Leclerc, 35042 Rennes, Cedex, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Thomas
authors.affiliation: ⊥CovalX AG, 8952 Zürich-Schlieren, Switzerland.
authors.forename: Alexis
authors.initials: A
authors.lastname: Nazabal
authors.affiliation: †Translation and Folding, UMR-CNRS 6290, Université de Rennes 1, Campus Beaulieu, 263 Avenue du Général Leclerc, 35042 Rennes, Cedex, France.
authors.forename: Cyrille
authors.initials: C
authors.lastname: Garnier
mesh_terms: D000818:Animals; D002850:Chromatography, Gel; D018841:HSP90 Heat-Shock Proteins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008027:Light; D018832:Molecular Chaperones / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification; D012542:Scattering, Radiation; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013552:Swine; D014461:Ultracentrifugation
chemical_list: C515652:AHSA1 protein, human; D018841:HSP90 Heat-Shock Proteins; D018832:Molecular Chaperones; D011994:Recombinant Proteins