In the cell, organelles, proteins, and signalling molecules are transported to specific locations along a network of filamentous tracks. Specialized enzymes called motor proteins bind to cargoes and move along the network by converting the chemical energy of ATP into mechanical work. The microtubule cytoskeleton consists of filaments that span the cell and serve as tracks for motor-based intracellular transport. We are interested in how these microtubule tracks regulate the movement and binding of motor proteins. Studying the mechanisms that control cargo transport contribute to our understanding of how this transport breaks down in neurons - a hallmark of neurodegenerative diseases such as ALS, Huntington’s disease, and Alzheimer’s disease. In our recently published work in the Biophysical Journal, we isolated microtubule cytoskeletons from cells and explored the effects of various microtubule-based regulatory factors on the motility of the motor protein kinesin. By tracking the transport of single kinesin molecules along native microtubule networks, we found that microtubule filaments organize into tightly packed bundles that act as highways for motor protein-driven transport. These results show that microtubules do not merely serve as passive tracks, but that the organization of the microtubules into bundles plays an important role in regulating transport. Our work is featured in the Collection “Microtubules and Motors”, highlighting recent advances in understanding the complex spatiotemporal control of intracellular transport using biophysical approaches.
Balabanian, L. Berger, C. L. & Hendricks, A. G. 2017. Acetylated Microtubules Are Preferentially Bundled Leading to Enhanced Kinesin-1 Motility. Biophysical Journal 113, 1151-1560