Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Mitochondrion. 2012 May;12(3):391-8. doi: 10.1016/j.mito.2012.02.004. Epub 2012 Mar 3.
The mitochondrial oxidative phosphorylation (OXPHOS) proteins are encoded by both nuclear and mitochondrial DNA. The nuclear-encoded OXPHOS mRNAs have specific subcellular localizations, but little is known about which localize near mitochondria. Here, we compared mRNAs in mitochondria-bound polysome fractions with those in cytosolic, free polysome fractions. mRNAs encoding hydrophobic OXPHOS proteins, which insert into the inner membrane, were localized near mitochondria. Conversely, OXPHOS gene which mRNAs were predominantly localized in cytosol had less than one transmembrane domain. The RNA-binding protein Y-box binding protein-1 is localized at the mitochondrial outer membrane and bound to the OXPHOS mRNAs. Our findings offer new insight into mitochondrial co-translational import in human cells.
线粒体氧化磷酸化（OXPHOS）蛋白由核 DNA 和线粒体 DNA 共同编码。核编码的 OXPHOS mRNA 具有特定的亚细胞定位，但对于哪些 mRNA 定位于线粒体附近知之甚少。在这里，我们比较了线粒体结合多核糖体分数中的 mRNA 与细胞质、游离多核糖体分数中的 mRNA。编码插入内膜的疏水性 OXPHOS 蛋白的 mRNA 定位于线粒体附近。相反，主要定位于细胞质中的 OXPHOS 基因的 mRNA 则少于一个跨膜结构域。RNA 结合蛋白 Y 盒结合蛋白-1位于线粒体的外膜上，并与 OXPHOS mRNA 结合。我们的发现为人类细胞中线粒体共翻译导入提供了新的见解。
