Møller Ian Max
Department of Molecular Biology and Genetics, Aarhus University, Slagelse, Denmark .
Physiol Plant. 2016 Jul;157(3):256-63. doi: 10.1111/ppl.12456. Epub 2016 Jun 1.
In this overview of recent trends in plant mitochondrial research, four questions are considered: (1) How large is the mitochondrial proteome? It appears to be in excess of 1500 proteins in a tissue at any given time. It is proposed that the fusion-fission frequently observed for plant mitochondria provides a vital mixing function ensuring that all low-abundance proteins are present in each mitochondrion at least some of the time. (2) What is the significance of posttranslational modifications (PTM) of proteins? As a result of PTM, many proteins are present in a very large number of slightly different forms. The most well-studied PTMs, such as protein phosphorylation, acetylation and reversible cysteine oxidation, are known to regulate mitochondrial function. Recent studies have provided examples of the importance of this regulation, but it remains a research area with a massive growth potential. (3) What is the role(s) of pentatricopeptide repeat (PPR) proteins in plant mitochondria? There is general agreement that PPR proteins are involved in RNA metabolism such as RNA editing. Recent comprehensive proteomic studies raise the question of how many of the potential 250-300 mitochondrial PPR proteins encoded in the nuclear DNA are required to be present for a mitochondrion to be able to grow and divide. (4) What is the mechanism(s) of retrograde signal transduction from the mitochondria to the nucleus? The nature of the signal transduction molecule is still unknown, but calcium ions, hydrogen peroxide and/or oxidized peptides are potential candidates. Recent results place a receptor for the activation of a group of nuclear genes on the endoplasmic reticulum, possibly close to ER-mitochondrial contact points.
在这篇关于植物线粒体研究近期趋势的综述中，我们思考了四个问题：（1）线粒体蛋白质组有多大？在任何给定时间，一个组织中的线粒体蛋白质组似乎超过1500种蛋白质。有人提出，植物线粒体中频繁观察到的融合-裂变提供了一种至关重要的混合功能，可确保所有低丰度蛋白质至少在某些时候存在于每个线粒体中。（2）蛋白质翻译后修饰（PTM）的意义是什么？由于PTM，许多蛋白质以大量略有不同的形式存在。最深入研究的PTM，如蛋白质磷酸化、乙酰化和可逆的半胱氨酸氧化，已知可调节线粒体功能。最近的研究提供了这种调节重要性的实例，但它仍然是一个具有巨大增长潜力的研究领域。（3）五肽重复（PPR）蛋白在植物线粒体中的作用是什么？人们普遍认为PPR蛋白参与RNA代谢，如RNA编辑。最近全面的蛋白质组学研究提出了一个问题，即核DNA中编码的250 - 300种潜在线粒体PPR蛋白中，有多少需要存在才能使线粒体能够生长和分裂。（4）从线粒体到细胞核的逆行信号转导机制是什么？信号转导分子的性质仍然未知，但钙离子、过氧化氢和/或氧化肽是潜在的候选者。最近的结果表明，一组核基因激活的受体位于内质网上，可能靠近内质网 - 线粒体接触点。
