Van Ael Elke, Fransen Marc
Katholieke Universiteit Leuven, Faculty of Medicine, Department of Molecular Cell Biology, Division of Pharmacology, Campus Gasthuisberg, Herestraat 49 bus 601, 3000 Leuven, Belgium.
Biochim Biophys Acta. 2006 Dec;1763(12):1629-38. doi: 10.1016/j.bbamcr.2006.08.020. Epub 2006 Aug 25.
Peroxisomal membrane proteins (PMPs) are encoded by the nuclear genome and translated on cytoplasmic ribosomes. Newly synthesized PMPs can be targeted directly from the cytoplasm to peroxisomes or travel to peroxisomes via the endoplasmic reticulum (ER). The mechanisms responsible for the targeting of these proteins to the peroxisomal membrane are still rather poorly understood. However, it is clear that the trafficking of PMPs to peroxisomes depends on the presence of cis-acting targeting signals, called mPTSs. These mPTSs show great variability both in the identity and number of requisite residues. An emerging view is that mPTSs consist of at least two functionally distinct domains: a targeting element, which directs the newly synthesized PMP from the cytoplasm to its target membrane, and a membrane-anchoring sequence, which is required for the permanent insertion of the protein into the peroxisomal membrane. In this review, we summarize our knowledge of the mPTSs currently identified.
过氧化物酶体膜蛋白（PMPs）由核基因组编码并在细胞质核糖体上翻译。新合成的PMPs可以直接从细胞质靶向到过氧化物酶体，或者通过内质网（ER）转运到过氧化物酶体。这些蛋白质靶向过氧化物酶体膜的机制仍然了解甚少。然而，很明显，PMPs向过氧化物酶体的运输取决于顺式作用靶向信号（称为mPTSs）的存在。这些mPTSs在必需残基的性质和数量上都表现出很大的变异性。一种新出现的观点认为，mPTSs至少由两个功能不同的结构域组成：一个靶向元件，它将新合成的PMP从细胞质引导到其靶膜；一个膜锚定序列，它是蛋白质永久插入过氧化物酶体膜所必需的。在这篇综述中，我们总结了目前已鉴定的mPTSs的相关知识。
