Mitochondrial Lon regulates apoptosis through the association with Hsp60-mtHsp70 complex
Journal
Cell Death & Disease
Journal Volume
6
Pages
e1642
Date Issued
2015
Author(s)
Abstract
Human Lon protease is a mitochondrial matrix protein with several functions, including protein degradation, mitochondrial DNA (mtDNA) binding, and chaperone activity. Lon is currently emerging as an important regulator of mitochondria-contributed tumorigenesis due to its overexpression in cancer cells. To understand the mechanism of increased Lon in tumor cells, we studied the interactome to identify the chaperone Lon-associated proteins by proteomics approaches using the cells overexpressing Lon. In the present study, we designed a method connecting co-immunoprecipitation (Co-IP) to in-solution digestion for the shotgun mass spectrometry. We identified 76 proteins that were putative Lon-associated proteins that participated in mitochondrial chaperone system, cellular metabolism and energy, cell death and survival, and mtDNA stability. The association between Lon and NDUFS8 or Hsp60-mtHsp70 complex was confirmed by Co-IP and immunofluorescence co-localization assay. We then found that the protein stability/level of Hsp60-mtHsp70 complex depends on the level of Lon under oxidative stress. Most importantly, the ability of increased Lon-inhibited apoptosis is dependent on Hsp60 that binds p53 to inhibit apoptosis. These results suggest that the mechanism underlying cell survival regulated by Lon is mediated by the maintenance of the protein stability of Hsp60-mtHsp70 complex. This new knowledge of chaperone Lon interactome will allow us to better understand the cellular mechanism of Lon in mitochondrial function and of its overexpression in enhancing cell survival and tumorigenesis. ? 2015 Macmillan Publishers Limited. All rights reserved.
SDGs
Other Subjects
caspase 3; chaperone; chaperonin 60; endopeptidase La; heat shock protein 70; iron sulfur protein; mitochondrial DNA; mitochondrial protein; NADH dehydrogenase (ubiquinone) iron sulfur protein 8; protein p53; reduced nicotinamide adenine dinucleotide dehydrogenase (ubiquinone); unclassified drug; chaperonin 60; endopeptidase La; heat shock protein 70; protein binding; apoptosis; Article; cancer cell; carcinogenesis; cell death; cell metabolism; cell stress; cell survival; cell viability; cellular distribution; controlled study; immunofluorescence; immunoprecipitation; in vitro study; mitochondrion; oxidative stress; priority journal; protein expression; protein protein interaction; protein stability; apoptosis; biology; cell line; enzymology; genetics; human; metabolism; mitochondrion; physiology; tandem mass spectrometry; Western blotting; Apoptosis; Blotting, Western; Cell Line; Cell Survival; Chaperonin 60; Computational Biology; HSP70 Heat-Shock Proteins; Humans; Immunoprecipitation; Mitochondria; Protease La; Protein Binding; Tandem Mass Spectrometry
Publisher
Springer Nature
Type
journal article