Laboratoire de Génétique Moléculaire, Ecole Normale Supérieure, 46 rue d'Ulm, Paris 75230, France.
EMBO Rep. 2010 Apr;11(4):285-91. doi: 10.1038/embor.2010.17. Epub 2010 Mar 12.
Although a considerable amount of data have been gathered on mitochondrial translocases, which control the import of a large number of nuclear-encoded proteins, the preceding steps taking place in the cytosol are poorly characterized. The localization of messenger RNAs (mRNAs) on the surface of mitochondria was recently shown to involve specific classes of protein and could be an important regulatory step. By using an improved statistical fluorescent in situ hybridization technique, we analysed the elements of the ATP2 open reading frame that control its mRNA asymmetric localization. The amino-terminal mitochondrial targeting peptide (MTS) and translation of two elements in the coding sequence, R1 and R2, were required for anchoring of ATP2 mRNA to mitochondria. Unexpectedly, any MTS can replace ATP2 MTS, whereas R1 and R2 are specifically required to maintain perimitochondrial mRNA localization. These data connect the well-known MTS-translocase interaction step with a site-specific translation step and offer a mechanistic description for a co-translational import process.
虽然已经收集到大量关于线粒体转位酶（控制大量核编码蛋白的输入）的数据，但细胞质中发生的前序步骤的特征描述还很少。信使 RNA（mRNA）在线粒体表面的定位最近显示涉及特定的蛋白质类别，可能是一个重要的调控步骤。我们使用改进的统计荧光原位杂交技术，分析了控制 ATP2 mRNA 不对称定位的开放阅读框的元素。氨基末端线粒体靶向肽（MTS）和编码序列中两个元素 R1 和 R2 的翻译对于 ATP2 mRNA 锚定在线粒体上是必需的。出乎意料的是，任何 MTS 都可以替代 ATP2 MTS，而 R1 和 R2 则是维持线粒体周围 mRNA 定位所必需的。这些数据将众所周知的 MTS-转位酶相互作用步骤与特定的翻译步骤联系起来，并为共翻译输入过程提供了一种机制描述。
