First published online December 7, 2007
Development 135, 102e (2008)
© The Company of Biologists Limited
Motor protein zips up dorsal closure
During dorsal closure (DC) in Drosophila embryos, actin-rich
filopodia extended by the leading edge cells of two epithelial sheets make
transient cell-cell contacts that allow the sheets to `zipper' together and
form permanent cell-adhesion structures. Now, Susan Parkhurst and co-workers
reveal that the Drosophila myosin XV homolog Sisyphus facilitates
these processes (see p.
53). Sisyphus - an actin-based motor protein - contains a
microtubule-binding MyTH4 domain and a cargo-binding FERM domain. The
researchers show that Sisyphus is expressed at high levels in the leading edge
cells and in their filopodia during the zippering phase of DC. RNAi knockdown
of Sisyphus, they report, disrupts the correct alignment of cells on opposing
sides of the fusing epithelial sheets and the adhesion of cells in the final
zippering phase. They also identify several putative Sisyphus cargos,
including DE-cadherin (which is involved in filopodia-mediated adhesion) and
several microtubule-linked proteins. Overall, the researchers propose that
Sisyphus regulates filopodia dynamics during DC by coordinating actin and
microtubule cytoskeleton components.
Related articles in Development:
- Sisyphus, the Drosophila myosin XV homolog, traffics within filopodia transporting key sensory and adhesion cargos
- Raymond Liu, Sarah Woolner, James E. Johndrow, David Metzger, Adriana Flores, and Susan M. Parkhurst
Development 2008 135: 53-63.
[Abstract]
[Full Text]
