Plant Actin-Depolymerizing Factors Possess Opposing Biochemical Properties Arising from Key Amino Acid Changes throughout Evolution
Plant Actin-Depolymerizing Factors Possess Opposing Biochemical Properties Arising from Key Amino Acid Changes throughout Evolution
复制标题
植物肌动蛋白解聚因子具有相反的生化特性，这是由整个进化过程中关键氨基酸的变化引起的
DOI：
10.1105/tpc.16.00690
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发表时间：
2017-02-01
期刊：
影响因子：
11.6
通讯作者：
Xiang, Yun
中科院分区：
文献类型：
--
作者：
Nan, Qiong;Qian, Dong;Xiang, Yun
旁系同源物的功能分化是进化创新的重要遗传来源。肌动蛋白解聚因子 (ADF) 是最重要的肌动蛋白结合蛋白之一，通过其保守的 F-肌动蛋白切断或解聚活性参与肌动蛋白细胞骨架结构的生成和重塑。在植物中，ADF 与肌动蛋白共同进化，但它们的生化特性不同。不幸的是，大多数植物 ADF 的生化功能及其功能差异的潜在机制仍不清楚。在这里，体外生化分析表明拟南芥中的所有 11 个 ADF 基因都表现出相反的生化特性。亚类 III ADF 从保守的 F-肌动蛋白解聚（D 型）功能进化而来的 F-肌动蛋白捆绑（B 型）功能，亚类 I ADF 具有增强的 D 型功能。通过追踪祖先蛋白质的历史突变位点，在拟南芥和多种植物中鉴定出了影响这些蛋白质生化功能的几个基本氨基酸残基，这表明ADF的生化分歧在被子植物的进化过程中得到了保守。重要的是，由内含子滑动事件引起的亚类 III ADF 的 N 端延伸对于 D 型功能向 B 型功能的改变是必不可少的。我们得出的结论是，这些 N 端延伸和几个保守突变的进化产生了来自假定祖先的植物 ADF 的多种生化功能。
Functional divergence in paralogs is an important genetic source of evolutionary innovation. Actin-depolymerizing factors (ADFs) are among the most important actin binding proteins and are involved in generating and remodeling actin cytoskeletal architecture via their conserved F-actin severing or depolymerizing activity. In plants, ADFs coevolved with actin, but their biochemical properties are diverse. Unfortunately, the biochemical function of most plant ADFs and the potential mechanisms of their functional divergence remain unclear. Here, in vitro biochemical analyses demonstrated that all 11 ADF genes in Arabidopsis thaliana exhibit opposing biochemical properties. Subclass III ADFs evolved F-actin bundling (B-type) function from conserved F-actin depolymerizing (D-type) function, and subclass I ADFs have enhanced D-type function. By tracking historical mutation sites on ancestral proteins, several fundamental amino acid residues affecting the biochemical functions of these proteins were identified in Arabidopsis and various plants, suggesting that the biochemical divergence of ADFs has been conserved during the evolution of angiosperm plants. Importantly, N-terminal extensions on subclass III ADFs that arose from intron-sliding events are indispensable for the alteration of D-type to B-type function. We conclude that the evolution of these N-terminal extensions and several conserved mutations produced the diverse biochemical functions of plant ADFs from a putative ancestor.