Armadillo Coactivates Transcription Driven by the Product of the Drosophila Segment Polarity Gene dTCF

• Published in: Cell 1997-03, Vol.88 (6), p.789-799
• Main Authors: van de Wetering, Marc, Cavallo, Robert, Dooijes, Dennis, van Beest, Moniek, van Es, Johan, Loureiro, Joseph, Ypma, Arne, Hursh, Deborah, Jones, Tamara, Bejsovec, Amy, Peifer, Mark, Mortin, Mark, Clevers, Hans
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Armadillo Domain Proteins; Body Patterning - genetics; Chromosome Mapping; Cloning, Molecular; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Drosophila; Drosophila Proteins; Female; Gene Expression Regulation, Developmental - physiology; Genes, Insect; High Mobility Group Proteins - genetics; High Mobility Group Proteins - metabolism; Insect Proteins - genetics; Insect Proteins - metabolism; Lymphoid Enhancer-Binding Factor 1; Male; Molecular Sequence Data; Mutation - physiology; Polymerase Chain Reaction; Proto-Oncogene Proteins - physiology; Repressor Proteins - genetics; Repressor Proteins - metabolism; Signal Transduction - physiology; Trans-Activators; Transcription Factors - genetics; Transcription Factors - metabolism; Transcription, Genetic - physiology; Wnt1 Protein
• ISSN: 0092-8674; 1097-4172
• DOI: 10.1016/S0092-8674(00)81925-X

The vertebrate transcription factors TCF (T cell factor) and LEF (lymphocyte enhancer binding factor) interact with β-catenin and are hypothesized to mediate Wingless/Wnt signaling. We have cloned a maternally expressed Drosophila TCF family member, dTCF. dTCF binds a canonical TCF DNA motif and interacts with the β-catenin homolog Armadillo. Previous studies have identified two regions in Armadillo required for Wingless signaling. One of these interacts with dTCF, while the other constitutes a transactivation domain. Mutations in dTCF and expression of a dominant-negative dTCF transgene cause a segment polarity phenotype and affect expression of the Wingless target genes engrailed and Ultrabithorax. Epistasis analysis positions dTCF downstream of armadillo. The Armadillo–dTCF complex mediates Wingless signaling as a bipartite transcription factor.