Kin I kinesins are microtubule-destabilizing enzymes
Kin I kinesins are microtubule-destabilizing enzymes
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DOI：
10.1016/s0092-8674(00)80960-5
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发表时间：
1999-01-08
期刊：
影响因子：
64.5
通讯作者：
Walczak, CE
中科院分区：
文献类型：
--
作者：
Desai, A;Verma, S;Walczak, CE
通过对纯化蛋白的体外分析，我们发现XKCM1和XKIF2是内部催化域(Kin I)Kinesin亚家族的两个不同成员，它们通过一种新的机制催化破坏微管的稳定。XKCM1和XKIF2都通过直接靶向微管末端而影响微管的稳定性，在微管末端它们会引起不稳定的构象变化。ATP水解法通过解离微管解聚时释放的XKCM1/XKIF2-微管蛋白二聚体复合体，回收XKCM1/XKIF2进行多轮作用。这些结果确立了Kin I是一种破坏微管稳定的酶，从机制上将它们与使用ATP水解酶沿微管转运的Kinesin超家族成员区分开来，并对微管动力学的调节以及Kinesin超家族的细胞内功能和进化具有重要的意义。
Using in vitro assays with purified proteins, we show that XKCM1 and XKIF2, two distinct members of the internal catalytic domain (Kin I) kinesin subfamily, catalytically destabilize microtubules using a novel mechanism. Both XKCM1 and XKIF2 influence microtubule stability by targeting directly to microtubule ends where they induce a destabilizing conformational change. ATP hydrolysis recycles XKCM1/XKIF2 for multiple rounds of action by dissociating a XKCM1/ XKIF2-tubulin dimer complex released upon microtubule depolymerization. These results establish Kin I kinesins as microtubule-destabilizing enzymes, distinguish them mechanistically from kinesin superfamily members that use ATP hydrolysis to translocate along microtubules, and have important implications for the regulation of microtubule dynamics and for the intracellular functions and evolution of the kinesin superfamily.