Brotzakis Z Faidon, Lindstedt Philip R, Taylor Ross J, Rinauro Dillon J, Gallagher Nicholas C T, Bernardes Gonçalo J L, Vendruscolo Michele
Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K.
Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028 Lisboa, Portugal.
ACS Cent Sci. 2021 Dec 22;7(12):1986-1995. doi: 10.1021/acscentsci.1c00585. Epub 2021 Dec 8.
Tau is a microtubule-associated protein that regulates the stability of microtubules. We use metainference cryoelectron microscopy, an integrative structural biology approach, to determine an ensemble of conformations representing the structure and dynamics of a tau-microtubule complex comprising the entire microtubule-binding region of tau (residues 202-395). We thus identify the ground state of the complex and a series of excited states of lower populations. A comparison of the interactions in these different states reveals positions along the tau sequence that are important to determine the overall stability of the tau-microtubule complex. This analysis leads to the identification of positions where phosphorylation and acetylation events have destabilizing effects, which we validate by using site-specific post-translationally modified tau variants obtained by chemical mutagenesis. Taken together, these results illustrate how the simultaneous determination of ground and excited states of macromolecular complexes reveals functional and regulatory mechanisms.
tau蛋白是一种与微管相关的蛋白质，可调节微管的稳定性。我们使用元推理冷冻电子显微镜这一综合结构生物学方法，来确定一组构象，这些构象代表了包含tau蛋白整个微管结合区域（残基202 - 395）的tau - 微管复合物的结构和动力学。由此我们确定了该复合物的基态以及一系列较低丰度的激发态。对这些不同状态下相互作用的比较揭示了tau序列上对于确定tau - 微管复合物整体稳定性很重要的位置。该分析导致了对磷酸化和乙酰化事件具有去稳定作用的位置的识别，我们通过使用化学诱变获得的位点特异性翻译后修饰的tau变体对此进行了验证。综上所述，这些结果说明了同时确定大分子复合物的基态和激发态如何揭示功能和调节机制。
