In this review, we look at the processes that occur `behind the scenes' in Wnt signalling, within the Wnt-producing cells. The Wnt community has long been focused upon events that occur downstream of Wnt binding to its receptors, but the recent discovery that the maturation of the Wnt protein may have a profound effect on its signalling properties has excited great interest. In the last 2 years, several key regulators of Wnt production have been discovered, but our global understanding of this process remains relatively poor. Several models that reconcile former and recent observations of Wnt modification, sorting and secretion, and which highlight the potential of this emerging field, are presented here.
Wnt glycoproteins are extracellular ligands that can be found in many species, ranging from the sea anemone Nematostella vectensis to human(Kusserow et al., 2005). Wnts act as morphogens and control the patterning of the developing embryo...
