Venkatesh Sundararajan, Lee Jae, Singh Kamalendra, Lee Irene, Suzuki Carolyn K
Department of Biochemistry and Molecular Biology, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, 185 South Orange Avenue, MSB E-633, Newark, New Jersey 07103 USA.
Biochim Biophys Acta. 2012 Jan;1823(1):56-66. doi: 10.1016/j.bbamcr.2011.11.003. Epub 2011 Nov 18.
The AAA(+) Lon protease is a soluble single-ringed homo-oligomer, which represents the most streamlined operational unit mediating ATP-dependent proteolysis. Despite its simplicity, the architecture of Lon proteases exhibits a species-specific diversity. Homology modeling provides insights into the structural features that distinguish bacterial and human Lon proteases as hexameric complexes from yeast Lon, which is uniquely heptameric. The best-understood functions of mitochondrial Lon are linked to maintaining proteostasis under normal metabolic conditions, and preventing proteotoxicity during environmental and cellular stress. An intriguing property of human Lon is its specific binding to G-quadruplex DNA, and its association with the mitochondrial genome in cultured cells. A fraction of Lon preferentially binds to the control region of mitochondrial DNA where transcription and replication are initiated. Here, we present an overview of the diverse functions of mitochondrial Lon, as well as speculative perspectives on its role in protein and mtDNA quality control.
AAA(+) Lon蛋白酶是一种可溶性单环同型寡聚体，它是介导ATP依赖性蛋白水解的最简化操作单元。尽管结构简单，但Lon蛋白酶的结构表现出物种特异性多样性。同源建模有助于深入了解细菌和人类Lon蛋白酶作为六聚体复合物与酵母Lon（独特的七聚体）之间的结构特征差异。线粒体Lon最广为人知的功能与在正常代谢条件下维持蛋白质稳态以及在环境和细胞应激期间预防蛋白毒性有关。人类Lon的一个有趣特性是它与G-四链体DNA的特异性结合以及在培养细胞中与线粒体基因组的关联。一部分Lon优先结合线粒体DNA的控制区域，该区域启动转录和复制。在这里，我们概述了线粒体Lon的多种功能，以及对其在蛋白质和线粒体DNA质量控制中作用的推测性观点。
