Journal of Proteomics & Bioinformatics
Open Access
ISSN: 0974-276X
ISSN: 0974-276X
Sixue Chen
University of Florida, USA
Scientific Tracks Abstracts: J Proteomics Bioinform
Reversibly oxidized cysteine sulfhydryl groups serve as redox sensors or targets of redox sensing. Here we report a new integrative proteomics method called cysTMTRAQ that combines two types of isobaric tags, isobaric tag for relative and absolute quantification (iTRAQ) and cysteine tandem mass tag (cysTMT) in one experiment. The method not only enables simultaneous analysis of cysteine redox changes and total protein level changes, but also allows determination of bona fide redox modified cysteines in proteins through correction of protein turnover. This technology has recently been applied to discover potential redox proteins in stomatal guard cells in response to the flagellin�s N-terminal domain�s 22-aa peptide (flg22) of Pseudomonas syringae pv. tomato str. DC3000 (PstDC3000). Stomatal closure was observed within 5 minutes of the flg22 treatment and became significant after 15 minutes of treatment. Reactive oxygen species (ROS) levels increased throughout the time course of treatment reached the peak at 15 minutes. Based on these results, three time points (15, 30 and 60 minutes) were selected for the cysTMTRAQ experiments. A total of 2144 proteins were identified, 677 contained cysteines with cysTMT labels 57 showed significant redox changes (q <0.05) after flg22 treatment. The identified redox proteins included superoxide dismutase, thiol peroxidase, disease resistance protein with LRR domain, germin-like protein, cyclophilin nitrilase 1. This study creates an inventory of potential redox switches highlights a protein redox regulatory mechanism in guard cell innate immunity as the first line of defense against pathogens.
Sixue Chen has completed his PhD from Shanghai Institue of Plant Physiology/ECNU and Post-doctoral studies from Freiburg University, KVL and UPENN. He is the Director of Proteomics and Mass Spectrometry core at the University of Florida. He has published more than 160 papers in reputed journals and has been serving as Editorial Board Member of Journal of Proteomics and Frontiers in Plant Science.
Email: schen@ufl.edu