Microtubules are dynamic biopolymers exerting forces when they grow or shorten. These forces are important in various contexts in living cells, such as during cell division, when microtubule ends attach to chromosomes and help them segregate to daughter cells. Microtubule ends transmit forces to cellular structures using teams of coupling protein molecules. Our research is focused on molecular and mechanical mechanisms by which these protein teams assemble and transmit the forces to cellular structures.
We hypothesize that regular microtubule lattice provides a platform for binding of force-coupling molecules, enhancing interactions between them, and thus creating multivalent protein complexes. To understand these multivalent interactions in detail, we reconstitute them in vitro using purified components, and use a range of experimental methods to understand their structure and dynamics.
We use electron cryo-tomography to reconstruct 3D organization of microtubule end-bound protein complexes. We use single-molecule fluorescence to study effects of these complexes on microtubule dynamics. We also probe these interactions under force to understand how microtubules push and pull on cellular structures.