title: XSEB4R, a novel RNA-binding protein involved in retinal cell differentiation downstream of bHLH proneural genes.
abstract: RNA-binding proteins play key roles in the post-transcriptional regulation of gene expression but so far they have not been studied extensively in the context of developmental processes. We report on the molecular cloning and spatio-temporal expression of a novel RNA-binding protein, XSEB4R, which is strongly expressed in the nervous system. This study is focused on the analysis of Xseb4R in the context of primary neurogenesis and retinogenesis. To study Xseb4R function during eye development, we set up a new protocol allowing in vivo lipofection of antisense morpholino oligonucleotides into the retina. The resulting XSEB4R knockdown causes an impairment of neuronal differentiation, with an increase in the number of glial cells. By contrast, our gain-of-function analysis demonstrates that Xseb4R strongly promotes neural differentiation. We also showed a similar function during primary neurogenesis. Consistent with this proneural effect, we found that in the open neural plate Xseb4R expression is upregulated by the proneural gene XNgnr1, as well as by the differentiation gene XNeuroD, but is inhibited by the Notch/Delta pathway. Altogether, our results suggest for the first time a proneural effect for a RNA-binding protein involved in the genetic network of retinogenesis.
authors.affiliation: Laboratoire d'Embryologie Moléculaire et Expérimentale, UMR CNRS 8080, Bâtiment 445, Université Paris XI, 91405 Orsay, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Boy
authors.forename: Jacob
authors.initials: J
authors.lastname: Souopgui
authors.forename: Marcos A
authors.initials: MA
authors.lastname: Amato
authors.forename: Maurice
authors.initials: M
authors.lastname: Wegnez
authors.forename: Tomas
authors.initials: T
authors.lastname: Pieler
authors.forename: Muriel
authors.initials: M
authors.lastname: Perron
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002454:Cell Differentiation; D004625:Embryo, Nonmammalian / Q000378:metabolism; D005822:Genetic Vectors; D008081:Liposomes; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D012160:Retina / Q000196:embryology* / Q000378:metabolism; D016415:Sequence Alignment; D014981:Xenopus; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D008081:Liposomes; D009841:Oligonucleotides; D016601:RNA-Binding Proteins; C482980:SEB4R protein, Xenopus; D029867:Xenopus Proteins