The RNA-binding protein XSeb4R: a positive regulator of VegT mRNA stability and translation that is required for germ layer formation in Xenopus

Jacob Souopgui; Barbara Rust,; Jessica Vanhomwegen; Janet Heasman; Kristine A. Henningfeld; Eric Bellefroid; Tomas Pieler

doi:10.1101/gad.479808

The RNA-binding protein XSeb4R: a positive regulator of VegT mRNA stability and translation that is required for germ layer formation in Xenopus

¹ Laboratoire d’Embryologie Moléculaire, Université Libre de Bruxelles, Institut de Biologie et de Médecine Moléculaires (IBMM), B-6041 Gosselies, Belgium;
² DFG Research Center for the Molecular Physiology of the Brain (CMPB), Department of Developmental Biochemistry, University of Goettingen, 37077 Goettingen, Germany;
³ Division of Developmental Biology, Children’s Hospital Medical Center, Cincinnati, Ohio 45229, USA

↵4 These authors contributed equally to this work.

Abstract

VegT represents a localized maternal determinant essentially required for endoderm formation in Xenopus. Here, we report on the identification of the RNA-binding protein XSeb4R as a positive regulator of VegT. XSeb4R interacts directly with the 3′-untranslated region of VegT mRNA, stabilizes it, and stimulates translation. Ablation of XSeb4R activity results in impairment of endoderm and mesoderm formation, while ectopic expression of XSeb4R in ectodermal cells induces endodermal and mesodermal gene expression. These observations unravel a novel mode of VegT regulation at the post-transcriptional level that is essential for germ layer formation in Xenopus.

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