Identification of essential sequence motifs in the node/notochord enhancer of Foxa2 (Hnf3beta) gene that are conserved across vertebrate species

• Published in: Mechanisms of development 2001-04, Vol.102 (1-2), p.57-66
• Main Authors: Nishizaki, Y, Shimazu, K, Kondoh, H, Sasaki, H
• Format: Article
• Language: English
• Subjects: Amino Acid Motifs; Amino Acid Sequence; Animals; Base Sequence; beta-Galactosidase - metabolism; Chick Embryo; Cloning, Molecular; Conserved Sequence; DNA-Binding Proteins - chemistry; DNA-Binding Proteins - genetics; Embryo, Mammalian - metabolism; Embryo, Nonmammalian; Enhancer Elements, Genetic; Evolution, Molecular; Fishes - embryology; Gene Deletion; Hepatocyte Nuclear Factor 3-beta; Mice; Mice, Transgenic; Models, Genetic; Molecular Sequence Data; Notochord - embryology; Nuclear Proteins - chemistry; Nuclear Proteins - genetics; Protein Binding; Sequence Homology, Amino Acid; Tissue Distribution; Transcription Factors; Transgenes
• ISSN: 0925-4773
• DOI: 10.1016/S0925-4773(01)00281-7

The expression of a winged-helix transcription factor, Foxa2/HNF3beta, is essential for development of the node and the notochord. We examined the node/notochord enhancer of mouse Foxa2 for sequence motifs conserved across vertebrate species. We cloned Foxa2 genes from chicken and fish, and identified the respective node/notochord enhancers that were active in transgenic mouse embryos. Comparison of the sequences of the enhancers revealed three evolutionally conserved sequence motifs, CS1, CS2 and CS3. Mutational analysis of the mouse enhancer indicated that CS3 is indispensable for gene expression in the node and the notochord, while CS1 and CS2 are required to augment enhancer activity. These motifs do not correspond to the consensus binding sequences of transcription factors known to be involved in node/notochord development.