We are using TIRF microscopy to study the mechanisms of microtubule bundling by Arabidopsis MAP65 protein at single molecule resolution.
Bundling is necessary for higher-order organization of the cortical microtubule cytoskeleton. In plants, the MAP65 family of proteins is the major microtubule bundling factor. We want to know which features of the MAP65 proteins are important for cross-linking microtubules and whether these proteins affect the assembly dynamics of microtubules within bundles. To address these questions, we are reconstituting microtubule bundling in a cell-free in vitro system using TIRF microscopy.
Basic scheme for reconstituting microtubule dynamics and bundling using TIRF microscopy.
(A) Example of microtubule bundling in the presence of MAP 65 protein. (B) Meshwork of bundled microtubules as a result of MAP 65 activity.