Quantitative analysis of the impact of a human pathogenic mutation on the CCT5 chaperonin subunit using a proxy archaeal ortholog

Biochemistry and Biophysics Reports

Francesco Cappello¹  Everly Conway de Macario²  Alberto J.L. Macario²  Jatin Narang³  D. Travis Gallagher³  Dario Spigolon³  Frank T. Robb³  Adrian Velazquez-Campoy⁴  Pier Luigi San Biagio⁵  Donatella Bulone⁵ 

[1] Department of Biomedicine and Clinical Neurosciences, Human Anatomy Section, University of Palermo, Palermo, Italy;Euro-Mediterranean Institute of Science and Technology (IEMEST), Palermo, Italy;Institute for Bioscience and Biotechnology Research (IBBR), Rockville, MD, USA;Institute of Biocomputation and Physics of Complex Systems (BIFI), Joint Units: BIFI-IQFR and GBsC-CSIC,Universidad de Zaragoza, Zaragoza, Spain;Institute of Biophysics, UOS Palermo, National Research Council, Italy;

关键词: Chaperonopathies;    CCT5;    Pyrococcus furiosus;    Chaperonin;    Protein calorimetry;    Neuropathy;   

DOI  :  10.1016/j.bbrep.2017.07.011

来源: DOAJ

【 摘 要 】

The human chaperonin complex is a ~ 1 MDa nanomachine composed of two octameric rings formed from eight similar but non-identical subunits called CCT. Here, we are elucidating the mechanism of a heritable CCT5 subunit mutation that causes profound neuropathy in humans. In previous work, we introduced an equivalent mutation in an archaeal chaperonin that assembles into two octameric rings like in humans but in which all subunits are identical. We reported that the hexadecamer formed by the mutant subunit is unstable with impaired chaperoning functions. This study quantifies the loss of structural stability in the hexadecamer due to the pathogenic mutation, using differential scanning calorimetry (DSC) and isothermal titration calorimetry (ITC). The disassembly of the wild type complex, which is tightly coupled with subunit denaturation, was decoupled by the mutation without affecting the stability of individual subunits. Our results verify the effectiveness of the homo-hexadecameric archaeal chaperonin as a proxy to assess the impact of subtle defects in heterologous systems with mutations in a single subunit.

【 授权许可】

Unknown