Investigation of the biological relevance of reducing systems of 1-Cys peroxiredoxins in plants

• Grant number: 14/07593-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: October 01, 2014
• End date: February 28, 2017
• Field of knowledge: Biological Sciences - Biochemistry - Metabolism and Bioenergetics
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Luis Eduardo Soares Netto
• Grantee: Maria Cristina Mingues Spinola
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 13/07937-8 - Redoxome - Redox Processes in Biomedicine, AP.CEPID

Abstract

It is growing the amount of evidence that peroxides, among the various ROS (Reactive Oxygen Species), play a physiological role in cell signaling. On the other hand, the peroxide levels in cells are controlled by various mechanisms, especially Cys-based, thiol-dependent peroxidases named peroxiredoxins (Prxs) that have been recently recognized as key players in the redox metabolism. These enzymes can be divided into two classes: 1-Cys Prx and 2-Cys Prx, according to the number of cysteines involved in the catalytic cycle. The 2-Cys Prxs are relatively well characterized. In contrast, 1-Cys Prx are considerably less characterized, including in terms of the identification of its biological reducing agent. Our group has shown that ascorbate can reduce 1-Cys Prx , changing the paradigm that peroxiredoxins are dependent thiol antioxidants. However, further evidence are need to address the biological relevance of this process . The group of Dr. Cejudo (CSIC/U.S., Spain) in which Dr Spinola was inserted in recent years has made significant contributions such as the demonstration that in plants , as well as ascorbate , thioredoxin systems can also reduce 1-Cys Prx . Moreover, plant cells have enormous amounts of ascorbate, which in principle favors the reduction of 1-Cys Prx by ascorbate. Thus, this research project aims to molecularly, physiologically and enzymatically characterize the reduction of 1-Cys Prx (Per1) plant by ascorbato and NTR (Thioredoxin reductase NADPH dependent). Thus, the proposed collaboration between Dr. Netto , Drª Spinola and Dr. Cejudo may unveil new frontiers in advancement of the understanding of the function of 1-Cys Prx plants and, consequently , of other organisms , with impacts in areas such as agriculture and medicine, considering that these enzymes has gained prominence as sensors of intracellular levels of peroxides. (AU)