生物
转录因子
抄写(语言学)
抑制因子
鱼藤酮
发起人
拟南芥
细胞生物学
分子生物学
遗传学
基因表达
基因
线粒体
突变体
语言学
哲学
作者
Estelle Giraud,Olivier Van Aken,Lois H.M. Ho,James Whelan
出处
期刊:Plant Physiology
[Oxford University Press]
日期:2009-05-29
卷期号:150 (3): 1286-1296
被引量:255
标识
DOI:10.1104/pp.109.139782
摘要
Abstract Plant cells integrate signals from external sources and from organelles to regulate gene expression, referred to as anterograde and retrograde signaling, respectively. Functional characterization of the promoter of ALTERNATIVE OXIDASE1a (AOX1a) from Arabidopsis (Arabidopsis thaliana), a marker for mitochondrial retrograde response, was carried out by testing the ability of the AOX1a promoter to drive expression of the reporter gene GUS. This approach identified a strong repressor element, designated the B element, that was necessary for an increased promoter activity in response to the mitochondrial complex I inhibitor rotenone. This element overlaps with a previously identified potential binding site for the transcription factor ABSCISIC ACID INSENSITIVE4 (ABI4). AOX1a promoter activity was fully derepressed in abi4 mutants and was unresponsive to rotenone. Furthermore, deletion of the B element of the AOX1a promoter resulted in increased GUS staining activity compared to the wild-type promoter in transgenic plants. Binding of the ABI4 transcription factor to this region of the AOX1a promoter was demonstrated by electromobility shift and yeast one-hybrid assays. Analysis of transcript abundance for AOX1a in abi4 mutant lines revealed significantly increased levels of AOX1a mRNA that could not be further induced by rotenone, consistent with the role of ABI4 as a repressor that is derepressed in response to rotenone. These results show that ABI4 plays a central role in mediating mitochondrial retrograde signals to induce the expression of AOX1a. Furthermore, they provide a molecular link between mitochondrial and chloroplast retrograde signaling, as ABI4 has been previously shown to act downstream of at least two chloroplast retrograde signaling pathways.
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