Transcription factor choice in the Hippo signaling
pathway: homothorax and yorkie regulation of the
microRNA bantam in the progenitor domain of the
Drosophila eye imaginal disc
H. Wayne Peng, Matthew Slattery and Richard S. Mann
Journal: GENES & DEVELOPMENT. 2009/09/17
Speaker: Yu-Cheng Huang
Adviser: Min-Lang Huang
Date: 2009/10/30
Abstract:
Controlling the switch from proliferation to differentiation is
important during animal development. The Hippo tumor suppressor
pathway controls the proliferation with transcriptional coactivactor
Yorkie (Yki) which regulates its target genes by interacting with a
DNA-binding protein, Scalloped (Sd) in wing development of
Drosophila. The authors discovered that Yki regulates downstream
genes by binding different DNA-binding protein, Homothorax (Hth)
and Teashirt (Tsh), in Drosophila eye imaginal disc. Hth and Tsh
interact with each other and repress the later-acting retinal
differentiation genes together in the uncommitted progenitor cells.
Hth and Tsh also promote cell proliferation and suppress cell
apoptosis in eye progenitor cells. The authors provide evidence that
Hth and Tsh interact to Yki physically for executing their function by
up-regulating the microRNA bantam. Hth and Tsh are bound to a DNA
sequence upstream of bantam hairpin in eye imaginal disc, arguing
that this regulation is direct. Basing on these date, they suggest that
the Hippo pathway uses different DNA-binding transcription factors
depending on different cellular background.