Rbb4l enhances TGF-beta/Nodal signaling and promotes zebrafish embryonic dorsolization
- Authors
- Tong, J.Y., Liu, X.F., and Jia, S.J.
- ID
- ZDB-PUB-130610-27
- Date
- 2013
- Source
- Yi chuan = Hereditas 35(4): 477-487 (Journal)
- Registered Authors
- Jia, Shunji, Tong, Jingyuan
- Keywords
- none
- MeSH Terms
-
- Animals
- Embryo, Nonmammalian/cytology
- Embryo, Nonmammalian/embryology*
- Embryo, Nonmammalian/metabolism
- Gene Expression Regulation, Developmental
- Nodal Protein/metabolism*
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Retinoblastoma-Binding Protein 4/genetics
- Retinoblastoma-Binding Protein 4/metabolism*
- Signal Transduction*
- Smad3 Protein/metabolism
- Transforming Growth Factor beta/metabolism*
- Zebrafish/embryology*
- Zebrafish/metabolism*
- Zebrafish Proteins/genetics
- Zebrafish Proteins/metabolism
- PubMed
- 23659938 Full text @ Yi Chuan
The TGF-β/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-β/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.