A tale of two α-tubulin tails.

Post-translational modifications of tubulin, such as the removal of the C-terminal tyrosine of a-tubulin, have long been proposed to influence the ability of microtubule motors to walk along the microtubule surface. This hypothesis has now been tested for cytoplasmic dynein-1 (dynein), revealing that active dynein-dynactin-adaptor complexes prefer to start moving on tyrosinated microtubules. This choice is governed by the p150 subunit of dynactin. Once moving, however, dynein is not choosy about whether the microtubule is tyrosinated or not.