Abstract
The redox state in plant mitochondria is affected by a wide range of environmental factors. Depending on the fluctuation of the redox state, the activity of several mitochondrial proteins may be subjected to redox regulation by the thioredoxin (TRX) system. In this study, we captured the potential TRX target proteins in mitochondria by TRX affinity chromatography, and identified them by proteomics technique. The mitochondrial soluble proteins determined as TRX targets contained enzymes which are involved in a variety of mitochondrial functions, such as TCA cycle, photorespiration, and protein synthesis. In addition, we identified some proteins which are associated with the respiratory electron transport and ATP synthesis in the solubilized membrane fraction. Notably, we revealed the interaction of TRX with alternative oxidase which plays a key role in ensuring cellular redox homeostasis especially under the stressful conditions. We present a list of TRX target proteins in mitochondria and discuss the possible regulatory system of the mitochondrial functions.
