A bacterial dynamin-like protein mediating nucleotide-independent membrane fusion
A bacterial dynamin-like protein mediating nucleotide-independent membrane fusion
复制标题
DOI：
10.1111/j.1365-2958.2011.07523.x
复制
发表时间：
2011-03-01
影响因子：
3.6
通讯作者：
Bramkamp, Marc
中科院分区：
文献类型：
--
作者：
Buermann, Frank;Ebert, Nina;Bramkamp, Marc
P>；Dynamins是一个大的GTP酶家族，参与关键的细胞过程，在那里它们介导膜分裂和融合事件。动力蛋白超家族并不局限于真核生物，可能有细菌起源，许多物种包含两个与有丝分裂素相关的基因的操纵子。然而，目前尚不清楚细菌动力素是促进膜分裂还是促进融合。枯草芽孢杆菌的动力蛋白DYNA是由两个动力蛋白基因融合而来的，它含有两个独立的动力蛋白亚基和GTP酶结构域。我们发现DyNA表现出严格的自动调节的GTP水解，并且通过GTP酶循环的进展是在DyNA寡聚体中协调进行的。此外，我们发现在体外，DyNA可以系膜并介导非核苷酸依赖的膜融合。这一过程只需要镁作为辅因子。我们的结果为动力蛋白样蛋白的膜融合提供了一组最低要求，并具有机制意义，特别是对于线粒体的融合。
P>Dynamins are a family of large GTPases that are involved in key cellular processes, where they mediate events of membrane fission and fusion. The dynamin superfamily is not restricted to eukaryotes but might have a bacterial origin, with many species containing an operon of two genes related to mitofusins. However, it is not clear whether bacterial dynamins promote membrane fission or fusion. The dynamin-like protein DynA of Bacillus subtilis is remarkable in that it arose from a gene fusion of two dynamins and contains two separate dynamin-like subunits and GTPase domains. We found that DynA exhibits strictly auto-regulated GTP hydrolysis, and that progress through the GTPase cycle is concerted within DynA oligomers. Furthermore, we show that DynA can tether membranes and mediates nucleotide-independent membrane fusion in vitro. This process merely requires magnesium as a cofactor. Our results provide a set of minimal requirements for membrane fusion by dynamin-like proteins and have mechanistic implications in particular for the fusion of mitochondria.