Hetzer M, Bilbao-Cortés D, Walther T C, Gruss O J, Mattaj I W
European Molecular Biology Laboratory, Heidelberg, Germany.
Mol Cell. 2000 Jun;5(6):1013-24. doi: 10.1016/s1097-2765(00)80266-x.
Nuclear formation in Xenopus egg extracts requires cytosol and is inhibited by GTP gamma S, indicating a requirement for GTPase activity. Nuclear envelope (NE) vesicle fusion is extensively inhibited by GTP gamma S and two mutant forms of the Ran GTPase, Q69L and T24N. Depletion of either Ran or RCC1, the exchange factor for Ran, from the assembly reaction also inhibits this step of NE formation. Ran depletion can be complemented by the addition of Ran loaded with either GTP or GDP but not with GTP gamma S. RCC1 depletion is only complemented by RCC1 itself or by RanGTP. Thus, generation of RanGTP by RCC1 and GTP hydrolysis by Ran are both required for the extensive membrane fusion events that lead to NE formation.
非洲爪蟾卵提取物中的细胞核形成需要胞质溶胶，并且受到GTPγS的抑制，这表明需要GTP酶活性。核膜（NE）囊泡融合受到GTPγS以及Ran GTP酶的两种突变形式Q69L和T24N的广泛抑制。从组装反应中去除Ran或Ran的交换因子RCC1也会抑制NE形成的这一步骤。Ran的缺失可以通过添加负载有GTP或GDP但不负载GTPγS的Ran来补充。RCC1的缺失仅由RCC1自身或RanGTP补充。因此，RCC1产生RanGTP以及Ran进行GTP水解对于导致NE形成的广泛膜融合事件都是必需的。
