High-resolution imaging reveals compartmentalization of mitochondrial protein synthesis in cultured human cells.
High-resolution imaging reveals compartmentalization of mitochondrial protein synthesis in cultured human cells.
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高分辨率成像揭示了培养的人类细胞中线粒体蛋白合成的分区化。
DOI：
10.1073/pnas.2008778118
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发表时间：
2021-02-09
影响因子：
11.1
通讯作者：
Lightowlers RN
中科院分区：
文献类型：
--
作者：
Zorkau M;Albus CA;Berlinguer-Palmini R;Chrzanowska-Lightowlers ZMA;Lightowlers RN
在不同物种的线粒体中，OXPHOS复合物主要存在于内陷的嵴膜中，而不是平行于线粒体外膜的内界膜（IBM）中。然而，IBM包含动态接触位点，富含从胞质溶胶输入蛋白质的易位酶。由于大多数OXPHOS组分是进口的，需要与mtDNA编码的组分整合在一起，线粒体内翻译发生在哪里？我们在此报告：1）用于以超分辨率可视化人类线粒体中的蛋白质合成的方法; 2）该合成在嵴膜处富集，优先于IBM;以及3）翻译位点在空间上与RNA颗粒分离，在所述RNA颗粒处发生RNA加工、成熟和线粒体装配。人类线粒体含有它们自己的基因组，线粒体DNA，其在线粒体基质中表达。该基因组编码13种重要的多肽，这些多肽是偶联氧化磷酸化（OXPHOS）的多亚基复合物的组分。容纳这些复合物的线粒体内膜包括与外膜平行的内界膜、形成嵴膜的内折叠和将两者分开的嵴连接。正是在这些嵴膜中，OXPHOS复合物已被证明存在于各种物种中。大多数OXPHOS亚基是核编码的，因此必须从细胞溶质通过与内界膜接触的外膜输入。由于蛋白质编码的成分也是这些复合物的组成部分，蛋白质合成发生在哪里？由于转录、mRNA加工、成熟和至少部分的线粒体装配过程发生在类核和空间并列的线粒体RNA颗粒上，蛋白质合成是否也在靠近这些实体的RNA颗粒上进行，或者它是否发生在这些位点的远端？我们已经采用了点击化学为基础的方法加上受激发射损耗纳米镜来解决这些问题。我们报告说，在培养的人类细胞中，在我们的方法的限制范围内，大多数线粒体蛋白质合成在嵴膜处被检测到，并且在空间上与RNA加工和成熟的位点分离。
In mitochondria from various species, the OXPHOS complexes reside mainly in the invaginated cristae membranes, as opposed to the inner boundary membrane (IBM) that parallels the mitochondrial outer membrane. However, the IBM contains dynamic contact sites enriched for translocases that import proteins from the cytosol. As the majority of OXPHOS components are imported and need to be integrated in assembly with the mtDNA-encoded components, where does intramitochondrial translation occur? Here we report: 1) a method for visualizing protein synthesis in human mitochondria at super resolution; 2) that synthesis is enriched at cristae membranes, in preference to the IBM; and 3) that sites of translation are spatially separated from RNA granules where RNA processing, maturation, and mitoribosomal assembly occur. Human mitochondria contain their own genome, mitochondrial DNA, that is expressed in the mitochondrial matrix. This genome encodes 13 vital polypeptides that are components of the multisubunit complexes that couple oxidative phosphorylation (OXPHOS). The inner mitochondrial membrane that houses these complexes comprises the inner boundary membrane that runs parallel to the outer membrane, infoldings that form the cristae membranes, and the cristae junctions that separate the two. It is in these cristae membranes that the OXPHOS complexes have been shown to reside in various species. The majority of the OXPHOS subunits are nuclear-encoded and must therefore be imported from the cytosol through the outer membrane at contact sites with the inner boundary membrane. As the mitochondrially encoded components are also integral members of these complexes, where does protein synthesis occur? As transcription, mRNA processing, maturation, and at least part of the mitoribosome assembly process occur at the nucleoid and the spatially juxtaposed mitochondrial RNA granules, is protein synthesis also performed at the RNA granules close to these entities, or does it occur distal to these sites? We have adapted a click chemistry-based method coupled with stimulated emission depletion nanoscopy to address these questions. We report that, in human cells in culture, within the limits of our methodology, the majority of mitochondrial protein synthesis is detected at the cristae membranes and is spatially separated from the sites of RNA processing and maturation.
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DOI：
10.1083/jcb.201401006
发表时间：
2014-03-31
期刊：
The Journal of cell biology
影响因子：
--
作者：
Pfanner N;van der Laan M;Amati P;Capaldi RA;Caudy AA;Chacinska A;Darshi M;Deckers M;Hoppins S;Icho T;Jakobs S;Ji J;Kozjak-Pavlovic V;Meisinger C;Odgren PR;Park SK;Rehling P;Reichert AS;Sheikh MS;Taylor SS;Tsuchida N;van der Bliek AM;van der Klei IJ;Weissman JS;Westermann B;Zha J;Neupert W;Nunnari J
通讯作者：
Nunnari J
影响因子：
12.4
作者：
Jakobs S;Stephan T;Ilgen P;Brüser C
通讯作者：
Brüser C
影响因子：
29
作者：
Jourdain AA;Koppen M;Wydro M;Rodley CD;Lightowlers RN;Chrzanowska-Lightowlers ZM;Martinou JC
通讯作者：
Martinou JC
影响因子：
5.4
作者：
Iborra, Francisco J.;Kimura, Hiroshi;Cook, Peter R.
通讯作者：
Cook, Peter R.
影响因子：
--
作者：
Chomyn, A
通讯作者：
Chomyn, A