Biosciences, CLES, Exeter University, Exeter, EX4 4QD, UK.
Department of Mathematics, Harrison Building, University of Exeter, Exeter, EX4 4QF, UK.
Commun Biol. 2020 Apr 3;3(1):161. doi: 10.1038/s42003-020-0872-x.
Mitochondria are highly pleomorphic, undergoing rounds of fission and fusion. Mitochondria are essential for energy conversion, with fusion favouring higher energy demand. Unlike fission, the molecular components involved in mitochondrial fusion in plants are unknown. Here, we show a role for the GTPase Miro2 in mitochondria interaction with the ER and its impacts on mitochondria fusion and motility. Mutations in AtMiro2's GTPase domain indicate that the active variant results in larger, fewer mitochondria which are attached more readily to the ER when compared with the inactive variant. These results are contrary to those in metazoans where Miro predominantly controls mitochondrial motility, with additional GTPases affecting fusion. Synthetically controlling mitochondrial fusion rates could fundamentally change plant physiology by altering the energy status of the cell. Furthermore, altering tethering to the ER could have profound effects on subcellular communication through altering the exchange required for pathogen defence.
线粒体具有高度的多形性，经历着一轮又一轮的裂变和融合。线粒体对于能量转换至关重要，融合有利于更高的能量需求。与裂变不同，植物中线粒体融合所涉及的分子成分尚不清楚。在这里，我们展示了 GTPase Miro2 在与内质网相互作用及其对线粒体融合和运动的影响中的作用。AtMiro2 的 GTPase 结构域的突变表明，与无活性变体相比，活性变体导致更大、更少的线粒体更容易与内质网结合。这些结果与后生动物中的情况相反，在后生动物中，Miro 主要控制线粒体的运动，而其他 GTPases 则影响融合。通过改变细胞的能量状态，人为地控制线粒体融合速率可能从根本上改变植物生理学。此外，通过改变与内质网的连接，可能会通过改变防御病原体所需的交换，对细胞内通讯产生深远影响。
