Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
XB-ART-7268
J Biol Chem June 28, 2002; 277 (26): 23872-81.

Cooperative interaction of Xvent-2 and GATA-2 in the activation of the ventral homeobox gene Xvent-1B.



Abstract
The Xvent family of homeobox transcription factors is essential for the establishment of the dorsal-ventral body axis during Xenopus embryogenesis. In contrast to Xvent-2B and other members of the Xvent-2 subfamily, Xvent-1B is not a direct response gene of bone morphogenetic protein-4 signaling. Xvent-1B is activated by Xvent-2, but CHX experiments revealed the requirement of additional factors. In this study, we report on the cooperative effect of Xvent-2 and the zinc finger transcription factor GATA-2 on the promoter of the Xvent-1B gene. We show that GATA-2 is a direct target gene of bone morphogenetic protein-4 and that GATA-2 interacts with Xvent-2 to activate transcription of Xvent-1B. Both transcription factors bind to distinct elements within the Xvent-1B promoter, and GATA-2 physically interacts with the C-terminal domain of Xvent-2. Promoter/reporter studies in Xenopus embryos revealed that full activation of Xvent-1B requires both Xvent-2 and GATA-2. Moreover, the two factors are sufficient to direct transcription of Xvent-1B in the presence of CHX at the ventral side of the embryo. The failure of both factors to activate Xvent-1B on the dorsal side suggests the existence of a dorsal inhibitor. This inhibitor is likely a component of the dorsal Wnt signaling pathway because nuclear translocation of beta-catenin before midblastula transition results in a suppression of Xvent-1B transcription.

PubMed ID: 11964398
Article link: J Biol Chem

Genes referenced: gata2 myc ventx1.1 ventx2.1 ventx2.2


Article Images: [+] show captions


Xenbase: The Xenopus Model Organism Knowledgebase.
Version: 4.14.0
Major funding for Xenbase is provided by grant P41 HD064556