Dynactin (red) does not get to the plus end of microtubules (green) that lack CLIP-170 (blue).
CLIP-170 is the prototypical microtubule plus-end binding protein. It changes microtubules dynamics by rescuing them from shrinking. Using RNAi, the authors now demonstrate that CLIP-170 is also needed to recruit dynactin to plus ends through the p150Glued dynactin subunit.
But first, CLIP-170 has to let go of itself. The authors found that CLIP-170 folds on itself through binding of its NH2 and COOH termini. In this position, its p150Glued binding site in the COOH terminus was inaccessible. Microtubules bound to CLIP-170 at the NH2 terminus near the site needed for the self-interaction. Once mounted on plus ends, CLIP-170 is probably open, thus freeing its COOH...
