Dosage-Dependent Proteome Response of Shewanella oneidensis MR-1 to Acute Chromate Challenge

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• 作者：Melissa R. Thompson ; Nathan C. VerBerkmoes ; Karuna Chourey ; Manesh Shah ; Dorothea K. Thompson ; Robert L. Hettich
• 刊名：Journal of Proteome Research
• 出版年：2007
• 出版时间：May 2007
• 年：2007
• 卷：6
• 期：5
• 页码：1745 - 1757
• 全文大小：377K
• 年卷期：v.6,no.5(May 2007)
• ISSN：1535-3907

文摘

Proteome alterations in the metal-reducing bacterium Shewanella oneidensis MR-1 in response todifferent acute dose challenges (0.3, 0.5, or 1 mM) of the toxic metal chromate [Cr(VI)] were characterizedwith multidimensional HPLC-MS/MS. Proteome measurements were performed and compared on bothquadrupole ion traps as well as linear trapping quadrupole mass spectrometers. We have found thatthe implementation of multidimensional liquid chromatography on-line with the rapid scanning, highthroughput linear trapping quadrupole platform resulted in a dramatic increase in the number ofmeasured peptides and, thus, the number of identified proteins. A total of 2406 functionally diverse,nonredundant proteins were identified in this study, representing a relatively deep proteome coveragefor this organism. The core molecular response to chromate challenge under all three concentrationsconsisted predominantly of proteins with annotated functions in transport and binding (e.g., componentsof the TonB1 iron transport system, TonB-dependent receptors, and sulfate transporters) as well as afunctionally undefined DNA-binding response regulator (SO2426) that might play a role in mediatingmetal stress responses. In addition, proteins annotated as a cytochrome c, a putative azoreductase,and various proteins involved in general stress protection were up-regulated at the higher Cr(VI) doses(0.5 and 1 mM) only. Proteins down-regulated in response to metal treatment were distributed acrossdiverse functional categories, with energy metabolism proteins dominating. The results presented inthis work demonstrate the dynamic dosage response of S. oneidensis to sub-toxic levels of chromate.