c-Jun (AP-1) activates BMP-4 transcription in Xenopus embryos
| Autor: | Sigrun Knöchel, Walter Knöchel, Annette Schuler-Metz |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Transcriptional Activation
Embryology animal structures Xenopus Molecular Sequence Data Bone Morphogenetic Protein 4 Xenopus Proteins Mediator Genes jun Transcription (biology) Animals Amino Acid Sequence Gene In Situ Hybridization DNA Primers Binding Sites Base Sequence Sequence Homology Amino Acid biology Intron Gene Expression Regulation Developmental RNA biology.organism_classification Molecular biology Introns Transcription Factor AP-1 Gastrulation AP-1 transcription factor Enhancer Elements Genetic Bone Morphogenetic Proteins embryonic structures Developmental Biology |
| Zdroj: | Mechanisms of Development. 98:29-36 |
| ISSN: | 0925-4773 |
| DOI: | 10.1016/s0925-4773(00)00448-2 |
| Popis: | Zygotic expression of the BMP-4 gene in Xenopus embryos is regulated by an auto-regulatory loop. Since AP-1 is known as a mediator of auto-regulatory loops both in the case of the Drosophila dpp and the mammalian TGF-b genes, we have analysed the potential of Xenopus cJun (AP-1) as a mediator of BMP-4 expression during Xenopus development. RNA injection experiments revealed that both heteromeric cFos/c-Jun and homodimeric c-Jun/c-Jun strongly activate BMP-4 transcription, whereas BMP signaling was found to activate the Xenopus cJun gene only at a rather low extent. In addition, the lack of zygotic c-Jun transcripts until the end of gastrulation should exclude a role of AP1 in the activation and the early expression of BMP-4 during gastrulation in vivo. However, at later stages of Xenopus development, we find a spatial overlap of c-Jun and BMP-4 transcripts which suggests that AP-1 might serve as an additional activatory component for the autoregulation of BMP-4. Promoter/reporter and gel mobility shift assays demonstrate multiple responsive sites for AP-1 in the 5 0 flanking region and two in the second intron of the BMP-4 gene. We further demonstrate that AP-1 acts independently of Xvent-2 which has recently been shown to mediate the early expression of BMP-4 in gastrula stage embryos. q 2000 Elsevier Science Ireland Ltd. All rights reserved. |
| Databáze: | OpenAIRE |
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