Minireview - Microtubules and Tubulin Oligomers: Shape Transitions and Assembly by Intrinsically Disordered Protein Tau and Cationic Biomolecules
Minireview - Microtubules and Tubulin Oligomers: Shape Transitions and Assembly by Intrinsically Disordered Protein Tau and Cationic Biomolecules
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迷你评论 - 微管和微管蛋白寡聚物：本质上无序的 Tau 蛋白和阳离子生物分子的形状转变和组装
DOI：
10.1021/acs.langmuir.9b02208
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发表时间：
2019
期刊：
影响因子：
3.9
通讯作者：
Feinstein, Stuart C.
中科院分区：
文献类型：
--
作者：
Safinya, Cyrus R.;Chung, Peter J.;Song, Chaeyeon;Li, Youli;Miller, Herbert P.;Choi, Myung Chul;Raviv, Uri;Ewert, Kai K.;Wilson, Leslie;Feinstein, Stuart C.
这篇迷你评论是纪念 Jacob N. Israelachvili 在分子间力和界面科学方面杰出研究生涯的特刊的一部分，我们介绍了微管 (MT) 和微管蛋白寡聚体与本质无序蛋白 (IDP) Tau、阳离子囊泡或多胺精胺 (4+) 的反应混合物中的结构、相行为和力的研究。裸 MT 平均由 13 个原丝 (PF) 组成，其中每个 PF 由 αβ-微管蛋白二聚体（即微管蛋白寡聚体）的线性堆叠组成。我们首先进行了一系列实验，这些实验证明了 PF 响应当地环境因素而改变形状的灵活性。首先，研究表明，MT 相关蛋白 (MAP) Tau 在与外表面结合后控制微管的直径，这意味着形成 MT 周界的 PF 横截面积发生形状变化。 MT 的直径也可以通过覆盖外表面的脂质双层膜的电荷密度来控制。我们进一步描述了一项实验研究，其中意外地发现生物学相关的多胺精胺（+4e）能够解聚紫杉醇稳定的微管，其效率随着温度的降低而增加。这种 MT 不稳定驱动了动态结构转变，在解聚剥离过程中，PF 由内向外弯曲，随后将环状弯曲的 PF 构建块重新组装成螺旋倒置微管蛋白小管阵列。最后，我们转向最近一项关于采用小角度 X 射线散射 (SAXS) 渗透压技术对 MT 束进行压力-距离测量的研究，该技术补充了 Jacob N. Israelachvili 开发的表面力装置技术。后面这些研究是极少数开始揭示 MAP Tau 在含有 GTP 且缺乏紫杉醇的 37 °C 反应混合物中介导的 MT 之间相互作用的精确性质的研究之一。
In this minireview, which is part of a special issue in honor of Jacob N. Israelachvili’s remarkable research career on intermolecular forces and interfacial science, we present studies of structures, phase behavior, and forces in reaction mixtures of microtubules (MTs) and tubulin oligomers with either intrinsically disordered protein (IDP) Tau, cationic vesicles, or the polyamine spermine (4+). Bare MTs consist of 13 protofilaments (PFs), on average, where each PF is made of a linear stack of αβ-tubulin dimers (i.e., tubulin oligomers). We begin with a series of experiments which demonstrate the flexibility of PFs toward shape changes in response to local environmental cues. First, studies show that MT-associated protein (MAP) Tau controls the diameter of microtubules upon binding to the outer surface, implying a shape change in the cross-sectional area of PFs forming the MT perimeter. The diameter of a MT may also be controlled by the charge density of a lipid bilayer membrane that coats the outer surface. We further describe an experimental study where it is unexpectedly found that the biologically relevant polyamine spermine (+4e) is able to depolymerizetaxol-stabilizedmicrotubules with efficiency that increases with decreasing temperature. This MT destabilization drives a dynamical structural transition where inside-out curving of PFs, during the depolymerization peeling process, is followed by reassembly of ring-like curved PF building blocks into an array of helical inverted tubulin tubules. We finally turn to a very recent study on pressure–distance measurements in bundles of MTs employing the small-angle X-ray scattering (SAXS)-osmotic pressure technique, which complements the surface-forces-apparatus technique developed by Jacob N. Israelachvili. These latter studies are among the very few which are beginning to shed light on the precise nature of the interactions between MTs mediated by MAP Tau in 37 °C reaction mixtures containing GTP and lacking taxol.