Stu2p binds tubulin and undergoes an open-to-closed conformational change.
Stu2p binds tubulin and undergoes an open-to-closed conformational change.
复制标题
Stu2p结合小管蛋白并经历开放式构象变化。
DOI：
10.1083/jcb.200511010
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发表时间：
2006-03-27
影响因子：
7.8
通讯作者：
Hyman, Anthony
中科院分区：
文献类型：
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作者：
Al-Bassam, Jawdat;van Breugel, Mark;Harrison, Stephen C;Hyman, Anthony
来自芽殖酵母的Stu 2 p属于微管相关蛋白（MAP）的保守的Dis 1/XMAP 215家族。这个家族中蛋白质的共同特征是在NH 2末端附近存在含HEAT重复序列的TOG结构域。我们研究了Stu 2 p的两个TOG结构域在体内和体外的功能。我们的数据表明，Stu 2 p通过两个独立的活动调节微管动力学。首先，Stu 2 p通过其第一个TOG结构域与单个游离微管蛋白异源二聚体结合。同源二聚体Stu 2 p从开放结构到封闭结构的大构象转变伴随着单个游离微管蛋白异二聚体的捕获。第二，Stu 2 p具有直接与微管末端结合的能力，至少部分是通过其第二个TOG结构域。这两种性质导致微管在体内的稳定，可能是通过微管蛋白二聚体在微管末端的加载。我们认为，这种微管调节机制是一个保守的功能的DIS 1/XMAP 215家庭的地图。
Stu2p from budding yeast belongs to the conserved Dis1/XMAP215 family of microtubule-associated proteins (MAPs). The common feature of proteins in this family is the presence of HEAT repeat–containing TOG domains near the NH2 terminus. We have investigated the functions of the two TOG domains of Stu2p in vivo and in vitro. Our data suggest that Stu2p regulates microtubule dynamics through two separate activities. First, Stu2p binds to a single free tubulin heterodimer through its first TOG domain. A large conformational transition in homodimeric Stu2p from an open structure to a closed one accompanies the capture of a single free tubulin heterodimer. Second, Stu2p has the capacity to associate directly with microtubule ends, at least in part, through its second TOG domain. These two properties lead to the stabilization of microtubules in vivo, perhaps by the loading of tubulin dimers at microtubule ends. We suggest that this mechanism of microtubule regulation is a conserved feature of the Dis1/XMAP215 family of MAPs.