NEW STUDY. Important developmental events are controlled by the Wnt/Wingless family of small signaling molecules in vertebrates. These molecules and the events they control are also implicated in the development of cancer in humans, where it is often dysregulated. Now researchers from the Sahlgrenska Academy report in Nature Cell Biology a novel mechanism regulating their secretion (Yamazaki et al., DOI 10.1038/ncb3325).
Examining this process in the model organism Drosophila melanogaster (the common fruitfly), researchers Yasuo Yamazaki and Ruth Palmer from the Sahlgrenska Academy, in collaboration with the group of Jean-Paul Vincent at the Francis Crick Institute in London, have identified a novel mechanism by which the Wingless signaling molecule (as it is known in the fruitfly Drosophila) is secreted from the cell. By following the Wingless molecule in the cell, they were able to show that Wingless is made in the apical part of the cell, but then transported within the cell to the basal membrane where its receptor is found – so called transcytosis. They were also able to identify a key molecule that regulates this process – Godzilla (an ubiquitin E3 ligase). Loss of Godzilla blocks Wingless transcytosis and with it the signaling events initiated by Wingless.
“With this new information, we now understand more about the complexity of Wingless signaling in intact tissues, in particular the phenomenon of transcytosis which has long been debated in the Wingless field”, says Yasuo Yamazaki.
“After this initial exciting finding, the question of how important Godzilla is in transcytosis of signaling molecules other than Wingless can now be explored”, adds Ruth Palmer.