The Arabidopsis Class II Sirtuin Is a Lysine Deacetylase and Interacts with Mitochondrial Energy Metabolism
The Arabidopsis Class II Sirtuin Is a Lysine Deacetylase and Interacts with Mitochondrial Energy Metabolism
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DOI：
10.1104/pp.113.232496
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发表时间：
2014-03-01
期刊：
影响因子：
7.4
通讯作者：
Finkemeier, Iris
中科院分区：
文献类型：
--
作者：
Koenig, Ann-Christine;Hartl, Markus;Finkemeier, Iris
赖氨酸乙酰化对蛋白质的翻译后调控不仅发生在组蛋白上，而且也发生在动植物细胞器蛋白上。特别是，代谢酶的催化活性已被证明是由赖氨酸乙酰化调节。拟南芥（Arabidopsis thaliana）基因组编码两个预测sirtuin型赖氨酸脱乙酰酶，其中只有沉默信息调节因子2同源物（SRT 2）包含一个预测的线粒体靶向的前序列。在此，我们研究了SRT 2在拟南芥中的功能。我们证明，SRT 2功能作为一个赖氨酸脱乙酰酶在体外和体内。我们发现，SRT 2主要存在于线粒体内膜，并与少数主要参与能量代谢和代谢物转运的蛋白质复合物相互作用。这些蛋白质复合物中的几种，如ATP合酶和ATP/ADP载体，在srt 2功能丧失突变体中显示出赖氨酸乙酰化的增加。srt 2植物显示没有生长表型，而是代谢表型与糖，氨基酸和ADP含量的水平改变。此外，在这些品系中，呼吸与ATP合成的偶联减少，而线粒体对ADP的摄取显著增加。我们的研究结果表明，SRT 2是重要的微调线粒体能量代谢。
The posttranslational regulation of proteins by lysine (Lys) acetylation has recently emerged to occur not only on histones, but also on organellar proteins in plants and animals. In particular, the catalytic activities of metabolic enzymes have been shown to be regulated by Lys acetylation. The Arabidopsis (Arabidopsis thaliana) genome encodes two predicted sirtuin-type Lys deacetylases, of which only Silent Information Regulator2 homolog (SRT2) contains a predicted presequence for mitochondrial targeting. Here, we have investigated the function of SRT2 in Arabidopsis. We demonstrate that SRT2 functions as a Lys deacetylase in vitro and in vivo. We show that SRT2 resides predominantly at the inner mitochondrial membrane and interacts with a small number of protein complexes mainly involved in energy metabolism and metabolite transport. Several of these protein complexes, such as the ATP synthase and the ATP/ADP carriers, show an increase in Lys acetylation in srt2 loss-of-function mutants. The srt2 plants display no growth phenotype but rather a metabolic phenotype with altered levels in sugars, amino acids, and ADP contents. Furthermore, coupling of respiration to ATP synthesis is decreased in these lines, while the ADP uptake into mitochondria is significantly increased. Our results indicate that SRT2 is important in fine-tuning mitochondrial energy metabolism.