Institute of Biology - Plant Physiology, Martin Luther University Halle-Wittenberg, Weinbergweg 10, 06120, Halle/Saale, Germany.
Photosynth Res. 2018 Dec;138(3):335-343. doi: 10.1007/s11120-018-0543-7. Epub 2018 Jun 26.
Dual targeting of a nuclearly encoded protein into two different cell organelles is an exceptional event in eukaryotic cells. Yet, the frequency of such dual targeting is remarkably high in case of mitochondria and chloroplasts, the two endosymbiotic organelles of plant cells. In most instances, it is mediated by "ambiguous" transit peptides, which recognize both organelles as the target. A number of different approaches including in silico, in organello as well as both transient and stable in vivo assays are established to determine the targeting specificity of such transit peptides. In this review, we will describe and compare these approaches and discuss the potential role of this unusual targeting process. Furthermore, we will present a hypothetical scenario how dual targeting might have arisen during evolution.
将核编码蛋白靶向到两个不同的细胞器是真核细胞中的一种特殊事件。然而，在植物细胞的两个内共生细胞器线粒体和叶绿体中，这种双重靶向的频率非常高。在大多数情况下，这是由“模糊”的转运肽介导的，它可以识别两个细胞器作为靶标。已经建立了许多不同的方法，包括计算机模拟、体外以及瞬时和稳定的体内测定，以确定这种转运肽的靶向特异性。在这篇综述中，我们将描述和比较这些方法，并讨论这种不寻常的靶向过程的潜在作用。此外，我们还将提出一个假设的情景，说明双重靶向是如何在进化过程中产生的。
