Research article

Identification of novel proteins affected by rotenone in mitochondria of dopaminergic cells

Jinghua Jin^1,2 , Jeanne Davis¹ , David Zhu¹ , Daniel T Kashima¹ , Marc Leroueil¹ , Catherine Pan¹ , Kathleen S Montine¹ and Jing Zhang¹

¹  Department of Pathology, University of Washington School of Medicine, Seattle, WA, USA

²  Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China

author email corresponding author email

BMC Neuroscience 2007, 8:67doi:10.1186/1471-2202-8-67

Published:	16 August 2007

Abstract

Background

Many studies have shown that mitochondrial dysfunction, complex I inhibition in particular, is involved in the pathogenesis of Parkinson's disease (PD). Rotenone, a specific inhibitor of mitochondrial complex I, has been shown to produce neurodegeneration in rats as well as in many cellular models that closely resemble PD. However, the mechanisms through which complex I dysfunction might produce neurotoxicity are as yet unknown. A comprehensive analysis of the mitochondrial protein expression profile affected by rotenone can provide important insight into the role of mitochondrial dysfunction in PD.

Results

Here, we present our findings using a recently developed proteomic technology called SILAC (stable isotope labeling by amino acids in cell culture) combined with polyacrylamide gel electrophoresis and liquid chromatography-tandem mass spectrometry to compare the mitochondrial protein profiles of MES cells (a dopaminergic cell line) exposed to rotenone versus control. We identified 1722 proteins, 950 of which are already designated as mitochondrial proteins based on database search. Among these 950 mitochondrial proteins, 110 displayed significant changes in relative abundance after rotenone treatment. Five of these selected proteins were further validated for their cellular location and/or treatment effect of rotenone. Among them, two were confirmed by confocal microscopy for mitochondrial localization and three were confirmed by Western blotting (WB) for their regulation by rotenone.

Conclusion

Our findings represent the first report of these mitochondrial proteins affected by rotenone; further characterization of these proteins may shed more light on PD pathogenesis.