Modulation of the microtubule cytoskeleton: a role for a divergent canonical Wnt pathway.

Wnts are signalling molecules implicated in normal development and in disease. Although Wnts can signal through three pathways, the canonical or beta-catenin pathway has been particularly studied because of its crucial role in embryonic patterning and cancer. It is well accepted that canonical Wnt signalling regulates gene expression by modulating the levels of beta-catenin, a co-activator of Tcf/Lef transcription factors. However, a divergent canonical Wnt pathway directly regulates the microtubule cytoskeleton. Interestingly, many components of the pathway are associated with the cytoskeleton and can act locally. Here I discuss recent evidence supporting a direct role for canonical Wnt signalling in microtubule regulation, and how this function sheds a new light into the mechanisms that regulate cell-fate determination and polarization.