CAP-Gly proteins contribute to microtubule-dependent trafficking via interactions with the C-terminal aromatic residue of α-tubulin.

In mammals, the C-terminal tyrosine residue of α-tubulin is subjected to removal/re-addition cycles resulting in tyrosinated microtubules and detyrosinated Glu-microtubules. CLIP170 and its yeast ortholog (Bik1) interact weakly with Glu-microtubules. Recently, we described a Microtubule- Rho1- and Bik1-dependent mechanism involved in Snc1 routing. Here, we further show a contribution of the yeast p150Glued ortholog (Nip100) in Snc1 trafficking. Both CLIP170 and p150Glued are CAP-Gly-containing proteins that belong to the microtubule +end-tracking protein family (known as +Tips). We discuss the +Tips-dependent role of microtubules in trafficking, the role of CAP-Gly proteins as possible molecular links between microtubules and vesicles, as well as the contribution of the Rho1-GTPase to the regulation of the +Tips repertoire and the partners associated with microtubules.