Imaging GTP-bound tubulin: from cellular to in vitro assembled microtubules.

Microtubules display a very dynamic behavior, and the presence of the guanosine-triphosphate (GTP) cap at the plus ends of microtubules is essential to regulate microtubule dynamics. Dimitrov et al. (2008) showed that GTP-tubulin is present not only at the plus ends but also in discrete locations along the microtubule lattice. These GTP islands were proposed to contribute to rescue events. Studying the localization of GTP-tubulin in microtubules is essential to better comprehend some core aspects in the regulation of microtubule dynamics. In this chapter, we recapitulate essential tools to study the GTP-tubulin using the recombinant antibody MB11 from permeabilized cells to in vitro assays.