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Updated: May 23, 2026

Ratiometric Biosensors that Measure Mitochondrial Redox State and ATP in Living Yeast Cells
Published on: July 22, 2013
A systems biological analysis links ROS metabolism to mitochondrial protein quality control
Axel Kowald1, Andrea Hamann, Sandra Zintel
1Humboldt-Universität zu Berlin, Institute for Biology, Theoretical Biophysics, Invalidenstrasse 42, 10115 Berlin, Germany.
Abstract:
The analyses of previously generated Podospora anserina strains in which the mitochondrial superoxide dismutase, PaSOD3, is increased in abundance, revealed unexpected results, which, at first glance, are contradictory to the 'free radical theory of aging' (FRTA). To re-analyze these results, we performed additional experiments and developed a mathematical model consisting of a set of differential equations describing the time course of various ROS (reactive oxygen species), components of the cellular antioxidant system (PaSOD3 and mitochondrial peroxiredoxin, PaPRX1), and PaCLPP, a mitochondrial matrix protease involved in protein quality control. Incorporating these components we could identify a positive feed-back loop and demonstrate that the role of superoxide as the primary ROS responsible for age-related molecular damage is more complicated than originally stated by the FRTA. Our study is a first step towards the integration of the various pathways known to be involved in the control of biological aging.
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