Crumbs under the skin

Forming an epithelium, one of the most basic requirements of multicellular life, requires sophisticated coordination of cellular polarity with morphogenesis. Using a Drosophila model system, Medina et al. (page 941) have now characterized an important link between polarity cues and the spectrin-based membrane skeleton.

In fly epithelia, the apical transmembrane protein Crumbs is essential for both polarization and proper cellular morphogenesis. The new work shows that Crumbs can recruit both β_H spectrin and DMoesin to its cytoplasmic tail, which was already known to interact with the polarity-determining proteins Stardust and Discs-lost. The interactions suggest that Crumbs may recruit the spectrin-based membrane skeleton in response to polarity cues, stabilizing the zonula adherens and helping to define the structure of the apical end of the cell.It is interesting to note that the interaction...