Inactivation of Mitochondrial Complex I Induces the Expression of a Twin Cysteine Protein that Targets and Affects Cytosolic, Chloroplastidic and Mitochondrial Function

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• 作者：Yan Wang¹ ; Wenhui Lyu¹ ; Oliver Berkowitz¹ ; Jordan D. Radomiljac¹ ; Simon R. Law² ; Monika W. Murcha³ ; Chris Carrie⁴ ; Pedro F. Teixeira⁵ ; Beata Kmiec⁵ ; Owen Duncan³ ; Olivier Van Aken³ ; Reena Narsai¹ ; Elzbieta Glaser⁵ ; Shaobai Huang³ ; Ute Roessner⁶ ; A. Harvey Millar³ ; James Whelan¹ ; ^{j.whelan@latrobe.edu.au" class="auth_mail" title="E-mail the corresponding author}
• 关键词：mitochondria ; complex I ; retrograde signaling ; chloroplast ; cytosol
• 刊名：Molecular Plant
• 出版年：2016
• 出版时间：2 May 2016
• 年：2016
• 卷：9
• 期：5
• 页码：696-710
• 全文大小：1515 K

文摘

At12Cys-1 (At5g64400) and At12Cys-2 (At5g09570) are two closely related isogenes that encode small, twin cysteine proteins, typically located in mitochondria. At12Cys-2 transcript is induced in a variety of mutants with disrupted mitochondrial proteins, but an increase in At12Cys protein is only detected in mutants with reduced mitochondrial complex I abundance. Induction of At12Cys protein in mutants that lack mitochondrial complex I is accompanied by At12Cys protein located in mitochondria, chloroplasts, and the cytosol. Biochemical analyses revealed that even single gene deletions, i.e., At12cys-1 or At12cys-2, have an effect on mitochondrial and chloroplast functions. However, only double mutants, i.e., At12cys-1:At12cys-2, affect the abundance of protein and mRNA transcripts encoding translation elongation factors as well as rRNA abundance. Blue native PAGE showed that At12Cys co-migrated with mitochondrial supercomplex I + III. Likewise, deletion of both At12cys-1 and At12cys-2 genes, but not single gene deletions, results in enhanced tolerance to drought and light stress and increased anti-oxidant capacity. The induction and multiple localization of At12Cys upon a reduction in complex I abundance provides a mechanism to specifically signal mitochondrial dysfunction to the cytosol and then beyond to other organelles in the cell.