1/27 – Ao Ma, University of Illinois at Chicago

Speaker: Ao Ma

Associate Professor, Department of Bioengineering, UIC

Title: Dynamic instability from non-equilibrium structural transitions on the energy landscape of microtubule

Abstract:

Microtubules are the backbone of the cytoskeleton and vital to numerous cellular processes. The central dogma of microtubules is that all their functions are driven by dynamic instability, but its mechanism has remained unresolved for over thirty years due to conceptual difficulties inherent in the dominant GTP-cap framework. Here we present a new conceptual framework: dynamic instability is non-equilibrium structural transitions on the energy landscape of microtubule and is determined by its topology (e.g. basins, barriers), which we infer from steric constraints of tubulin structures and the geometry of microtubule lattice. From the resulting energy landscape, we developed a physically rigorous structural mechano-chemical model that, for the first time, unifies all the phenomena of dynamic instability (e.g. growth, shortening, catastrophe, rescue and pausing at both plus and minus ends) and enables us to reproduce them in kinetic simulations.