Department of Pharmacology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA.
J Cell Biochem. 2012 Jul;113(7):2193-200. doi: 10.1002/jcb.24113.
Multidimensional proteins such as glyceraldehyde-3-phosphate dehydrogenase (GAPDH) exhibit distinct activities unrelated to their originally identified functions. Apart from glycolysis, GAPDH participates in iron metabolism, membrane trafficking, histone biosynthesis, the maintenance of DNA integrity and receptor mediated cell signaling. Further, multifunctional proteins exhibit distinct changes in their subcellular localization reflecting their new activities. As such, GAPDH is not only a cytosolic protein but is localized in the membrane, the nucleus, polysomes, the ER and the Golgi. In addition, although the initial subcellular localizations of multifunctional proteins may be of significance, dynamic changes in intracellular distribution may occur as a consequence of those new activities. As such, regulatory mechanisms may exist through which cells control multifunctional protein expression as a function of their subcellular localization. The temporal sequence through which subcellular translocation and the acquisition of new GAPDH functions is considered as well as post-translational modification as a basis for its intracellular transport.
多种蛋白，如甘油醛-3-磷酸脱氢酶（GAPDH），表现出与其最初确定的功能无关的独特活性。除糖酵解外，GAPDH 还参与铁代谢、膜运输、组蛋白生物合成、DNA 完整性的维持和受体介导的细胞信号转导。此外，多功能蛋白在亚细胞定位上表现出明显的变化，反映了它们的新活性。因此，GAPDH 不仅是一种细胞质蛋白，还定位于膜、核、多核糖体、内质网和高尔基体。此外，尽管多功能蛋白的初始亚细胞定位可能具有重要意义，但由于这些新活性，细胞内分布的动态变化可能会发生。因此，可能存在调节机制，细胞可以根据其亚细胞定位来控制多功能蛋白的表达。本文还考虑了亚细胞易位和获得新 GAPDH 功能的时间顺序，以及作为其细胞内运输基础的翻译后修饰。
