Human Hsp60 with its mitochondrial import signal occurs in solution as heptamers and tetradecamers remarkably stable over a wide range of concentrations

Silvia Vilasi; Rita Carrotta; Maria Rosalia Mangione; Claudia Campanella; Fabio Librizzi; Loredana Randazzo; Vincenzo Martorana; Antonella Marino Gammazza; Maria Grazia Ortore; Annalisa Vilasi; Gabriella Pocsfalvi; Giosalba Burgio; Davide Corona; Antonio Palumbo Piccionello; Giovanni Zummo; Donatella Bulone; Everly Conway de Macario; Alberto J L Macario; Pier Luigi San Biagio; Francesco Cappello

doi:10.1371/journal.pone.0097657

Human Hsp60 with its mitochondrial import signal occurs in solution as heptamers and tetradecamers remarkably stable over a wide range of concentrations

PLoS One. 2014 May 15;9(5):e97657. doi: 10.1371/journal.pone.0097657. eCollection 2014.

Authors

Silvia Vilasi¹, Rita Carrotta¹, Maria Rosalia Mangione¹, Claudia Campanella², Fabio Librizzi¹, Loredana Randazzo¹, Vincenzo Martorana¹, Antonella Marino Gammazza², Maria Grazia Ortore³, Annalisa Vilasi⁴, Gabriella Pocsfalvi⁴, Giosalba Burgio⁵, Davide Corona⁵, Antonio Palumbo Piccionello⁶, Giovanni Zummo⁷, Donatella Bulone¹, Everly Conway de Macario⁸, Alberto J L Macario⁹, Pier Luigi San Biagio¹, Francesco Cappello¹⁰

Affiliations

¹ Institute of Biophysics, National Research Council, Palermo, Italy.
² Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo, Palermo, Italy; Euro-Mediterranean Institute of Science and Technology, Palermo, Italy.
³ Department of Life and Environmental Sciences and National Interuniversity Consortium for the Physical Sciences of Matter, Marche Polytechnic University, Ancona, Italy.
⁴ Institute of Biosciences and Bioresources, National Research Council, Napoli, Italy.
⁵ Department of biological chemical and pharmaceutical sciences and technologies, University of Palermo, Palermo, Italy.
⁶ Institute of Biophysics, National Research Council, Palermo, Italy; Department of biological chemical and pharmaceutical sciences and technologies, University of Palermo, Palermo, Italy.
⁷ Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo, Palermo, Italy.
⁸ Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore, and Institute of Marine and Environmental Technology, Columbus Center, Baltimore, Maryland, United States of America.
⁹ Euro-Mediterranean Institute of Science and Technology, Palermo, Italy; Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore, and Institute of Marine and Environmental Technology, Columbus Center, Baltimore, Maryland, United States of America.
¹⁰ Institute of Biophysics, National Research Council, Palermo, Italy; Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo, Palermo, Italy; Euro-Mediterranean Institute of Science and Technology, Palermo, Italy.

Abstract

It has been established that Hsp60 can accumulate in the cytosol in various pathological conditions, including cancer and chronic inflammatory diseases. Part or all of the cytosolic Hsp60 could be naïve, namely, bear the mitochondrial import signal (MIS), but neither the structure nor the in solution oligomeric organization of this cytosolic molecule has still been elucidated. Here we present a detailed study of the structure and self-organization of naïve cytosolic Hsp60 in solution. Results were obtained by different biophysical methods (light and X ray scattering, single molecule spectroscopy and hydrodynamics) that all together allowed us to assay a wide range of concentrations of Hsp60. We found that Naïve Hsp60 in aqueous solution is assembled in very stable heptamers and tetradecamers at all concentrations assayed, without any trace of monomer presence.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adenosine Triphosphatases / chemistry
Cell-Free System
Chaperonin 60 / chemistry*
Cytosol / chemistry
Humans
Hydrolysis
Inflammation
Mitochondria / chemistry*
Mitochondrial Proteins / chemistry*
Protein Binding
Recombinant Proteins / chemistry
Scattering, Radiation
Spectrometry, Fluorescence

Substances

Chaperonin 60
HSPD1 protein, human
Mitochondrial Proteins
Recombinant Proteins
Adenosine Triphosphatases

Grants and funding

This work has been supported by Italian grant FIRB “Future in research” RBFR12SIPT MIND: "Multidisciplinary Investigations for the development of Neuro-protective Drugs". FC and AJLM were partially supported by Euro-Mediterranean Institute of Science and Technology (Italy). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.