Voos Wolfgang
Institut für Biochemie und Molekularbiologie IBMB, Universität Bonn, Nussallee 11, 53115 Bonn, Germany.
Biochim Biophys Acta. 2013 Feb;1833(2):388-99. doi: 10.1016/j.bbamcr.2012.06.005. Epub 2012 Jun 13.
As essential organelles, mitochondria are intimately integrated into the metabolism of a eukaryotic cell. The maintenance of the functional integrity of the mitochondrial proteome, also termed protein homeostasis, is facing many challenges both under normal and pathological conditions. First, since mitochondria are derived from bacterial ancestor cells, the proteins in this endosymbiotic organelle have a mixed origin. Only a few proteins are encoded on the mitochondrial genome, most genes for mitochondrial proteins reside in the nuclear genome of the host cell. This distribution requires a complex biogenesis of mitochondrial proteins, which are mostly synthesized in the cytosol and need to be imported into the organelle. Mitochondrial protein biogenesis usually therefore comprises complex folding and assembly processes to reach an enzymatically active state. In addition, specific protein quality control (PQC) processes avoid an accumulation of damaged or surplus polypeptides. Mitochondrial protein homeostasis is based on endogenous enzymatic components comprising a diverse set of chaperones and proteases that form an interconnected functional network. This review describes the different types of mitochondrial proteins with chaperone functions and covers the current knowledge of their roles in protein biogenesis, folding, proteolytic removal and prevention of aggregation, the principal reactions of protein homeostasis. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids.
作为重要的细胞器，线粒体与真核细胞的代谢紧密整合。线粒体蛋白质组功能完整性的维持，即蛋白质稳态，在正常和病理条件下都面临诸多挑战。首先，由于线粒体起源于细菌祖先细胞，这个内共生细胞器中的蛋白质来源混杂。只有少数蛋白质由线粒体基因组编码，大多数线粒体蛋白质的基因位于宿主细胞的核基因组中。这种分布需要线粒体蛋白质进行复杂的生物合成，这些蛋白质大多在细胞质中合成，然后需要导入到细胞器中。因此，线粒体蛋白质生物合成通常包括复杂的折叠和组装过程，以达到酶活性状态。此外，特定的蛋白质质量控制（PQC）过程可避免受损或多余多肽的积累。线粒体蛋白质稳态基于内源性酶成分，这些成分包括多种伴侣蛋白和蛋白酶，它们形成一个相互连接的功能网络。本综述描述了具有伴侣功能的不同类型线粒体蛋白质，并涵盖了它们在蛋白质生物合成、折叠、蛋白水解去除和防止聚集（蛋白质稳态的主要反应）中作用的当前知识。本文是名为：线粒体和质体中的蛋白质导入与质量控制的特刊的一部分。
