Models of post-translational protein translocation
Models of post-translational protein translocation
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DOI：
10.1016/s0006-3495(00)76471-x
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发表时间：
2000-11-01
影响因子：
3.4
通讯作者：
Elston, TC
中科院分区：
文献类型：
--
作者：
Elston, TC
细胞器 Hsp-70 是翻译后易位至内质网和线粒体所必需的。 Hsp-70 的功能作用尚不清楚。然而，已经提出了两种操作原则。动力冲程模型提出，Hsp-70 经历构象变化，将前体蛋白拉过易位孔，而在布朗棘轮模型中，Hsp-70 的作用只是阻止通过孔的向后滑动。对这两种机制进行了数学分析，并揭示了模型之间作为 Hsp-70 浓度函数的平均速度和有效扩散系数的行为存在定性差异。提出了一种仅依赖于当前实验技术来测量这两个量的实验方法。
Organellar Hsp-70 is required for post-translational translocation into the endoplasmic reticulum and mitochondria. The functional role played by Hsp-70 is unknown. However, two operating principles have been suggested. The power stroke model proposes that Hsp-70 undergoes a conformational change, which pulls the precursor protein through the translocation pore, whereas, in the Brownian ratchet model, the role of Hsp-70 is simply to block backsliding through the pore. A mathematical analysis of both mechanisms is presented and reveals that qualitative differences between the models occur in the behavior of the mean velocity and effective diffusion coefficient as a function of Hsp-70 concentration. An experimental method is proposed for measuring those two quantities that only relies on current experimental techniques.