EB1 interacts with outwardly curved and straight regions of the microtubule lattice
EB1 interacts with outwardly curved and straight regions of the microtubule lattice
复制标题
DOI：
10.1038/ncb3412
复制
发表时间：
2016-10-01
影响因子：
21.3
通讯作者：
Chretien, Denis
中科院分区：
文献类型：
--
作者：
Guesdon, Audrey;Bazilel, Franck;Chretien, Denis
EB1是一种微管正端跟踪蛋白，可识别微管中的GTP-微管蛋白二聚体（1-4），因此是研究生长微管末端GTP帽结构的独特探针（5,6）。在这里，我们将EB1与金纳米颗粒（EB1-金）结合，并通过低温电子断层扫描成像其与体外纯化微管蛋白组装的动态微管的相互作用。eb1 -金在GTP存在下组装的微管末端形成彗星，并与弯曲和直微管片的外表面以及微管晶格的封闭区域相互作用。在GTP存在下组装的微管，不同的GTP类似物或细胞提取物在其生长端显示类似的弯曲片，随着原丝数量的增加逐渐变直，直到它们闭合成管。总之，我们的数据提供了EB1与生长微管末端相互作用的独特结构信息。他们进一步提供了微管二聚体在微管组装和GTP-cap区域结构过程中所经历的构象变化的见解。
EB1 is a microtubule plus-end tracking protein that recognizes GTP-tubulin dimers in microtubules(1-4) and thus represents a unique probe to investigate the architecture of the GTP cap of growing microtubule ends(5,6). Here, we conjugated EB1 to gold nanoparticles (EB1-gold) and imaged by cryo-electron tomography its interaction with dynamic microtubules assembled in vitro from purified tubulin. EB1-gold forms comets at the ends of microtubules assembled in the presence of GTP, and interacts with the outer surface of curved and straight tubulin sheets as well as closed regions of the microtubule lattice. Microtubules assembled in the presence of GTP, different GTP analogues or cell extracts display similarly curved sheets at their growing ends, which gradually straighten as their protofilament number increases until they close into a tube. Together, our data provide unique structural information on the interaction of EB1 with growing microtubule ends. They further offer insights into the conformational changes that tubulin dimers undergo during microtubule assembly and the architecture of the GTP-cap region.