Structural Transformation Of Microtubules In The Presence Of Cationic Polymers

Microtubules (MTs) are cytoskeletal hollow cylinders of 25 nm diameter with walls comprised of linear protofilaments (PFs), head-to-tail arrangement of αβ-tubulin heterodimeric proteins. During the cell division, MTs at kinetochores switch phases between growth and shrinkage, which is governed by conformational transitions of tubulins. Cationic molecules can trigger the conformational changes of tubulins and assemble tubulins into aberrant assemblies, different with MT. We show our recent findings on the tubulin architectures, built in the presence of synthetic cationic polymers, and the underlying assembly mechanism. The assembly structures were studied using synchrotron small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM).