Functional profiling of asymmetrically-organized human CCT/TRiC chaperonin

Kazutaka Araki; Atsushi Suenaga; Hidewo Kusano; Riko Tanaka; Tomohisa Hatta; Tohru Natsume; Kazuhiko Fukui

doi:10.1016/j.bbrc.2016.10.120

Functional profiling of asymmetrically-organized human CCT/TRiC chaperonin

Biochem Biophys Res Commun. 2016 Dec 9;481(3-4):232-238. doi: 10.1016/j.bbrc.2016.10.120. Epub 2016 Oct 30.

Authors

Kazutaka Araki¹, Atsushi Suenaga², Hidewo Kusano³, Riko Tanaka³, Tomohisa Hatta⁴, Tohru Natsume⁵, Kazuhiko Fukui⁶

Affiliations

¹ Molecular Profiling Research Center for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Tokyo 135-0064, Japan. Electronic address: k-araki@aist.go.jp.
² Molecular Profiling Research Center for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Tokyo 135-0064, Japan; Department of Biosciences, College of Humanities and Sciences, Nihon University, 3-25-40 Sakurajosui Setagaya-Ku, Tokyo 156-8550, Japan.
³ Molecular Profiling Research Center for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Tokyo 135-0064, Japan.
⁴ Robotic Biology Institute, Inc., Tokyo 135-0064, Japan.
⁵ Molecular Profiling Research Center for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Tokyo 135-0064, Japan; Robotic Biology Institute, Inc., Tokyo 135-0064, Japan.
⁶ Molecular Profiling Research Center for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Tokyo 135-0064, Japan. Electronic address: k-fukui@aist.go.jp.

PMID: 27806916
DOI: 10.1016/j.bbrc.2016.10.120

Abstract

Molecular organization of the eukaryote chaperonin known as CCT/TRiC complex was recently clarified. Eight distinct subunits are uniquely organized, providing a favorable folding cavity for specific client proteins such as tubulin and actin. Because of its heterogeneous subunit composition, CCT complex has polarized inner faces, which may underlie an essential part of its chaperonin function. In this study, we structurally characterized the closed and open states of CCT complex, using molecular dynamics analyses. Our results showed that the inter-subunit interaction energies were asymmetrically distributed and were remodeled during conformational changes of CCT complex. In addition, exploration of redox related characteristics indicated changes in inner surface properties, including electrostatic potential, pK_a and exposure of inner cysteine thiol groups, between the closed and open states. Cysteine activation events were experimentally verified by interaction analyses, using tubulin as a model substrate. Our data highlighted the importance of dynamics-based structural profiling of asymmetrically oriented chaperonin function.

Keywords: CCT; Molecular simulation.

MeSH terms

Chaperonin Containing TCP-1 / chemistry
Chaperonin Containing TCP-1 / metabolism*
Computer Simulation
Cysteine / metabolism
HEK293 Cells
Humans
Models, Molecular
Oxidation-Reduction
Protein Binding
Protein Subunits / chemistry
Protein Subunits / metabolism
Static Electricity
Thermodynamics

Substances

Protein Subunits
Chaperonin Containing TCP-1
Cysteine