Abstract
Glutathione reductase (GR) plays an important role in the maintenance of correct redox status in cells. However, the global investigations of GR-modulated cellular responses including protein expressions and redox-regulations have yet to be elucidated. In this study, we cultured a human lung adenocarcinoma line CL1-0 and its GR-knockdown derivative CL1-0ΔGR to evaluate differential protein expression and redox-regulation of these two cell lines. We used lysine- and cysteine-labeling 2D-DIGE and MALDI-TOF MS analysis to monitor the protein expression and thiol-reactivity changes. Our approaches revealed that 34 identified proteins showed significant changes in protein expression, and 17 proteins showed significant changes in thiol reactivity, in response to GR-depletion. Several proteins that are involved in redox regulation, calcium signaling, cytoskeleton regulation and protein folding showed significant changes in expression, whereas proteins involved in redox-regulation, protein folding and glycolysis displayed changes in thiol reactivity. Furthermore, we also used CL1-0 and CL1-0ΔGR cells to evaluate their differential response to UVB-irradiation, and we identified 18 proteins that showed significant changes under UVB-irradiation in CL1-0ΔGR cells rather than in CL1-0 cells. Several proteins that are involved in protein folding, metabolism, protein biosynthesis and redox regulation showed significant changes in expression under UVB-irradiation with GR-depletion. In summary, the current study used a comprehensive lung adenocarcinoma-based proteomic approach for the identification of GR-modulated protein expression and redox-modification. To our knowledge, this is the first global proteomic and redox-proteomic analysis to investigate the role of GR in mammalian cell model.