Allosteric Regulation Points Control the Conformational Dynamics of the Molecular Chaperone Hsp90.
Heat shock protein 90 (Hsp90) is an ATP-dependent molecular chaperone responsible for the activation, maturation, and trafficking of several hundred client proteins in the cell. It is well known that (but not understood how) residues far away from Hsp90's nucleotide binding pocket can regulate its ATPase activity, a phenomenon called allosteric regulation. Here, the computational design of allosteric mutations was combined with in vitro and in vivo experiments to unravel nucleotide-responsive hot spots in the regulation of Hsp90. With this approach, we identified both activating and inhibiting regulation points and show that changes in those amino acids affect the conformational dynamics and ATPase activity of Hsp90 in vitro. Our observations that activating mutations loosen and inhibiting mutations rigidify the protein explain for the first time how Hsp90 changes in response to allosteric mutations. Additionally, mutations of these allosteric regulation points can be controlled by the interplay with Hsp90 co-chaperones, thus providing cells with an efficient mechanism of modifying Hsp90's intrinsic properties via different layers of regulation. Altogether, our results show that a framework for transmitting conformational information exists in the Hsp90 structure.
Center for Integrated Protein Science Munich (CIPSM) at the Department of Chemistry, Technische Universität München, Lichtenbergstraße 4, 85747 Garching, Germany.
Alexandra
A
Rehn
Istituto di Chimica del Riconoscimento Molecolare, CNR, Via Mario Bianco 9, 20131 Milano, Italy; IRCCS MultiMedica, Via Fantoli 16/15, 20138 Milano, Italy.
Elisabetta
E
Moroni
Center for Integrated Protein Science Munich (CIPSM) at the Department of Chemistry, Technische Universität München, Lichtenbergstraße 4, 85747 Garching, Germany.
Bettina K
BK
Zierer
Center for Integrated Protein Science Munich (CIPSM) at the Department of Chemistry, Technische Universität München, Lichtenbergstraße 4, 85747 Garching, Germany.
Franziska
F
Tippel
Istituto di Chimica del Riconoscimento Molecolare, CNR, Via Mario Bianco 9, 20131 Milano, Italy.
Giulia
G
Morra
Center for Integrated Protein Science Munich (CIPSM) at the Department of Chemistry, Technische Universität München, Lichtenbergstraße 4, 85747 Garching, Germany.
Christine
C
John
Center for Integrated Protein Science Munich (CIPSM) at the Department of Chemistry, Technische Universität München, Lichtenbergstraße 4, 85747 Garching, Germany.
Klaus
K
Richter
Istituto di Chimica del Riconoscimento Molecolare, CNR, Via Mario Bianco 9, 20131 Milano, Italy. Electronic address: giorgio.colombo@icrm.cnr.it.
Giorgio
G
Colombo
Center for Integrated Protein Science Munich (CIPSM) at the Department of Chemistry, Technische Universität München, Lichtenbergstraße 4, 85747 Garching, Germany. Electronic address: johannes.buchner@tum.de.
Johannes
J
Buchner
D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000378:metabolism*; D000494:Allosteric Regulation; D004252:DNA Mutational Analysis; D018841:HSP90 Heat-Shock Proteins / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D018832:Molecular Chaperones / Q000737:chemistry* / Q000378:metabolism*; D056004:Molecular Dynamics Simulation; D011487:Protein Conformation; D012441:Saccharomyces cerevisiae / Q000201:enzymology*
D018841:HSP90 Heat-Shock Proteins; D018832:Molecular Chaperones; D000251:Adenosine Triphosphatases
FRET; Hsp90; allosteric regulation; molecular chaperones; molecular dynamics simulations