RESUMO
The TGF-ß/Nodal signaling pathway plays an important role in the zebrafish dorsoventral patterning process. To further explore the function and mechanism of this signaling pathway, we identified a set of Smad2/3a interacting proteins by the yeast two-hybrid screen. Rbb4l (Retinoblastoma binding protein 4, like) is one of the identified proteins. Human RBBP4 (Retinoblastoma binding protein 4), the homolog of zebrafish Rbb4l, has been shown to form complexes with other chromatin modifiers, but its roles in embryonic development remain unknown. In this study, we showed that Rbb4l directly interacted with Smad3a and enhances TGF-ß/Nodal signaling. In zebrafish embryos, rbb4l overexpression resulted in an expanded expression of dorsal markers with a reduction of ventral markers expression, suggesting a dorsalizing function. On the contrary, rbb4l knockdown caused ventralized phenotype of the embryos at 24 hours post-fertilization (hpf). Furthermore, a series of rescue experiments showed that rbb4l failed to cause embryonic dorsalization in the absence of Nodal signal. Together, our data suggested that Rbb4l acts as an enhancer of Nodal/Smad2/3 signaling during embryogene-sis, and depends on the existence of Nodal signaling.
Assuntos
Embrião não Mamífero/embriologia , Proteína Nodal/metabolismo , Proteína 4 de Ligação ao Retinoblastoma/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/metabolismo , Animais , Embrião não Mamífero/citologia , Embrião não Mamífero/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteína 4 de Ligação ao Retinoblastoma/genética , Proteína Smad3/metabolismo , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismoRESUMO
As one of the most important vertebrate model systems, the zebrafish plays increasingly important roles in the field of life sciences. At present, zebrafish is widely used in studies on developmental biology, molecular biology, cell biology, genetics, neurobiology, oncology, immunology, marine biology, pharmacology, toxicology, and environmental protection. The zebrafish-based studies have led to many important discoveries that contribute to the development of modern life sciences. The zebrafish model system was introduced into China in the late 1990s; since then, the Chinese zebrafish community has being expanded fast with more influencing research outcomes, promoting a wide range of disciplines. This review gives an overview of zebrafish-based studies and representative findings in the mainland and Hong Kang of China, aiming to promote wider utilization of zebrafish for high-level studies.