Mean-field study of the role of lateral cracks in microtubule dynamics
Mean-field study of the role of lateral cracks in microtubule dynamics
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DOI：
10.1103/physreve.83.041905
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发表时间：
2011-04-08
影响因子：
2.4
通讯作者：
Alber, Mark S.
中科院分区：
文献类型：
--
作者：
Margolin, Gennady;Goodson, Holly V.;Alber, Mark S.
通过比较计算二聚体模型与其平均场近似得到的模拟结果，研究了宏观尺度上二聚体尺度过程与微管动力学之间的联系。平均场模型(MFM)的新奇之处在于它对原丝间裂纹的显式表示，以及直接纳入二聚体水平的动力学。由于包括了纵向和横向的二聚体相互作用，MFM是二维的，与以前的MTS理论模型形成对比。这是第一个预测和量化MT动力学关键特征的分析模型，例如(I)存在聚合所需的最小可溶性微管蛋白浓度(浓度表示为模型参数的函数)，(Ii)存在稳定增长和缩短阶段(以各自的速度给出)，以及(Iii)存在接近零速度的不稳定停顿状态。此外，还估计了不断增长的MT的GTP上限的大小。理论预测与数值模拟结果吻合较好。
A link between dimer-scale processes and microtubule (MT) dynamics at macroscale is studied by comparing simulations obtained using computational dimer-scale model with its mean-field approximation. The novelty of the mean-field model (MFM) is in its explicit representation of inter-protofilament cracks, as well as in the direct incorporation of the dimer-level kinetics. Due to inclusion of both longitudinal and lateral dimer interactions, the MFM is two dimensional, in contrast to previous theoretical models of MTs. It is the first analytical model that predicts and quantifies crucial features of MT dynamics such as (i) existence of a minimal soluble tubulin concentration needed for the polymerization (with concentration represented as a function of model parameters), (ii) existence of steady-state growth and shortening phases (given with their respective velocities), and (iii) existence of an unstable pause state near zero velocity. In addition, the size of the GTP cap of a growing MT is estimated. Theoretical predictions are shown to be in good agreement with the numerical simulations.