First published online September 28, 2007
Development 134, 2001e (2007)
© The Company of Biologists Limited
Hox function through collaboration
Hox proteins potentially regulate many targets within individual developing
tissues, but how they selectively regulate diverse target genes and activate
or repress target gene expression is poorly understood. To address these
questions, Walsh and Carroll investigated the repression of the spalt
(sal) gene by the Hox protein Ubx in the developing
Drosophila hindwing (haltere) (see
p. 3585). Using both
genetic and biochemical approaches, they found that two Smad proteins (Mad and
Med), which are required for sal activation in the wing, collaborate
with Ubx to directly repress sal in the haltere. This repression
occurs via a sal cis-regulatory element that contains closely spaced
Smad and Ubx binding sites and is perfectly conserved among four
Drosophila species. Because Smad and Ubx proteins appear not to
interact directly, the authors argue that they might instead `collaborate' to
co-regulate sal, and that collaboration might be a widespread
requirement for Hox function in which two or more regulatory proteins bind to
the same site but not to each other.
Related articles in Development:
- Collaboration between Smads and a Hox protein in target gene repression
- Christopher M. Walsh and Sean B. Carroll
Development 2007 134: 3585-3592.
[Abstract]
[Full Text]
