TY - JOUR
T1 - Molecular and Mechanical Causes of Microtubule Catastrophe and Aging
AU - Zakharov, Pavel
AU - Gudimchuk, Nikita
AU - Voevodin, Vladimir
AU - Tikhonravov, Alexander
AU - Ataullakhanov, Fazoil I.
AU - Grishchuk, Ekaterina L.
N1 - Publisher Copyright:
© 2015 by the Biophysical Society.
PY - 2015/12/15
Y1 - 2015/12/15
N2 - Tubulin polymers, microtubules, can switch abruptly from the assembly to shortening. These infrequent transitions, termed "catastrophes", affect numerous cellular processes but the underlying mechanisms are elusive. We approached this complex stochastic system using advanced coarse-grained molecular dynamics modeling of tubulin-tubulin interactions. Unlike in previous simplified models of dynamic microtubules, the catastrophes in this model arise owing to fluctuations in the composition and conformation of a growing microtubule tip, most notably in the number of protofilament curls. In our model, dynamic evolution of the stochastic microtubule tip configurations over a long timescale, known as the system's "aging", gives rise to the nonexponential distribution of microtubule lifetimes, consistent with experiment. We show that aging takes place in the absence of visible changes in the microtubule wall or tip, as this complex molecular-mechanical system evolves slowly and asymptotically toward the steady-state level of the catastrophe-promoting configurations. This new, to our knowledge, theoretical basis will assist detailed mechanistic investigations of the mechanisms of action of different microtubule-binding proteins and drugs, thereby enabling accurate control over the microtubule dynamics to treat various pathologies.
AB - Tubulin polymers, microtubules, can switch abruptly from the assembly to shortening. These infrequent transitions, termed "catastrophes", affect numerous cellular processes but the underlying mechanisms are elusive. We approached this complex stochastic system using advanced coarse-grained molecular dynamics modeling of tubulin-tubulin interactions. Unlike in previous simplified models of dynamic microtubules, the catastrophes in this model arise owing to fluctuations in the composition and conformation of a growing microtubule tip, most notably in the number of protofilament curls. In our model, dynamic evolution of the stochastic microtubule tip configurations over a long timescale, known as the system's "aging", gives rise to the nonexponential distribution of microtubule lifetimes, consistent with experiment. We show that aging takes place in the absence of visible changes in the microtubule wall or tip, as this complex molecular-mechanical system evolves slowly and asymptotically toward the steady-state level of the catastrophe-promoting configurations. This new, to our knowledge, theoretical basis will assist detailed mechanistic investigations of the mechanisms of action of different microtubule-binding proteins and drugs, thereby enabling accurate control over the microtubule dynamics to treat various pathologies.
UR - http://www.scopus.com/inward/record.url?scp=84954129965&partnerID=8YFLogxK
U2 - 10.1016/j.bpj.2015.10.048
DO - 10.1016/j.bpj.2015.10.048
M3 - Article
C2 - 26682815
AN - SCOPUS:84954129965
SN - 0006-3495
VL - 109
SP - 2574
EP - 2591
JO - Biophysical Journal
JF - Biophysical Journal
IS - 12
ER -