Dynamics of the COPII coat with GTP and stable analogues
Dynamics of the COPII coat with GTP and stable analogues
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DOI：
10.1038/35078500
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发表时间：
2001-06-01
影响因子：
21.3
通讯作者：
Schekman, R
中科院分区：
文献类型：
--
作者：
Antonny, B;Madden, D;Schekman, R
我们已经开发了一种测定法来监测COPII包衣在脂质体上的组装，该组装是真实的。我们发现，Sar 1 pGTP结合到脂质体，一轮的组装和拆卸的COPII涂层持续几秒钟。两个大的COPII复合物Sec 23/24 p和Sec 13/31 p几乎瞬间（在不到1秒的时间内）与Sar 1 pGTP掺杂的脂质体结合。由于Sec 13/31 p复合物使Sec 23/24 p的GTP酶激活蛋白活性加速10倍，这种结合之后是快速（小于10 s）分解。磷酸盐类似物BeFx的实验表明，Sec 23/24 p提供直接参与Sar 1 p上GTP水解的残基。
We have developed an assay to monitor the assembly of the COPII coat onto liposomes in real time. We show that with Sar1pGTP bound to liposomes, a single round of assembly and disassembly of the COPII coat lasts a few seconds. The two large COPII complexes Sec23/24p and Sec13/31p bind almost instantaneously (in less than 1 s) to Sar1pGTP-doped liposomes. This binding is followed by a fast (less than 10 s) disassembly due to a 10-fold acceleration of the GTPase-activating protein activity of Sec23/24p by the Sec13/31p complex. Experiments with the phosphate analogue BeFx suggest that Sec23/24p provides residues directly involved in GTP hydrolysis on Sar1p.