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Updated: Aug 6, 2026
10:23
Genome-wide Snapshot of Chromatin Regulators and States in Xenopus Embryos by ChIP-Seq
Published on: February 26, 2015
XCtBP is a XTcf-3 co-repressor with roles throughout Xenopus development
M Brannon1, J D Brown, R Bates
1Department of Biochemistry, Howard Hughes Medical Institute, Center for Developmental Biology, University of Washington School of Medicine, Seattle, Washington 98195-7350, USA. kimelman@u.washington.edu.
Development (Cambridge, England)
|June 22, 1999
Summary
XTcf-3, a Xenopus transcription factor, uses XCtBP as a co-repressor to regulate gene expression. This interaction is crucial for embryonic development, particularly head and notochord formation.
Area of Science:
- Developmental biology
- Molecular genetics
- Transcriptional regulation
Background:
- XTcf-3 is an HMG box transcription factor essential for Xenopus dorsal-ventral axis formation.
- It acts as a Wnt pathway effector, interacting with beta-catenin to activate or repress gene expression.
Purpose of the Study:
- To identify the C-terminal co-repressor interacting with XTcf-3.
- To investigate the role of this interaction in transcriptional repression and embryonic development.
Main Methods:
- Yeast three-hybrid screening to identify XTcf-3 interacting proteins.
- Co-immunoprecipitation and Western blotting to confirm protein interactions.
- Reporter gene assays to measure transcriptional activity.
- Generation and expression of an antimorphic protein (XCtBP/G4A) in Xenopus embryos.
Main Results:
- Xenopus C-terminal Binding Protein (XCtBP) was identified as the XTcf-3 C-terminal co-repressor.
- Two specific binding sites in XTcf-3 are essential for XCtBP interaction and repression.
- The antimorphic XCtBP/G4A activates siamois transcription by interacting with XTcf-3.
- Ectopic XCtBP/G4A expression affects head and notochord development.
Conclusions:
- XCtBP functions as a critical co-repressor for XTcf-3 in Xenopus development.
- The interaction between XTcf-3 and XCtBP is vital for regulating gene expression during embryogenesis.
- XCtBP/G4A serves as a valuable tool for studying XCtBP functions in developmental processes.
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