Tager J M, Aerts J M, van den Bogert C, Wanders R J
E.C. Slater Institute, University of Amsterdam, The Netherlands.
J Inherit Metab Dis. 1994;17(4):459-69. doi: 10.1007/BF00711361.
Newly synthesized polypeptides contain signals that direct them to the appropriate intracellular organelles and the organelles contain receptors that recognize the signals. Protein synthesis occurs either on free ribosomes or on ribosomes bound to the endoplasmic reticulum. The proteins synthesized on bound ribosomes are co-translationally translocated into the lumen of the endoplasmic reticulum and contain or acquire targeting information for retention in the endoplasmic reticulum or for sorting to lysosomes and other compartments of the secretory and endocytic pathways. Proteins synthesized on free ribosomes remain in the cytosol or contain signals for import into the nucleus, mitochondria or peroxisomes. The nature of the targeting signals and the mechanisms of import are discussed briefly. Examples are given of inborn errors of metabolism caused by incorrect or impaired incorporation of proteins into mitochondria, lysosomes or peroxisomes.
新合成的多肽含有将它们导向适当细胞内细胞器的信号，而这些细胞器含有识别这些信号的受体。蛋白质合成发生在游离核糖体上或与内质网结合的核糖体上。在结合核糖体上合成的蛋白质在翻译过程中被转运到内质网腔中，并含有或获得用于保留在内质网中或用于分选到溶酶体以及分泌和内吞途径的其他区室的靶向信息。在游离核糖体上合成的蛋白质保留在细胞质中，或含有导入细胞核、线粒体或过氧化物酶体的信号。本文简要讨论了靶向信号的性质和导入机制。文中给出了因蛋白质错误或受损并入线粒体、溶酶体或过氧化物酶体而导致的先天性代谢缺陷的例子。
