The RNA-binding protein, Vg1RBP, is required for pancreatic fate specification

Dev Biol. 2006 Apr 15;292(2):442-56. doi: 10.1016/j.ydbio.2006.01.022.


Signaling mechanisms underlying the induction of the pre-pancreatic tissue within the endoderm remain poorly understood. Through an expression cloning strategy, we have identified a previously uncharacterized pancreatic factor that we named Shirin. Interestingly, the non-coding RNA regulatory sequence (3 UTR) of Shirin is sufficient to induce insulin expression in Xenopus embryos. Biochemical studies demonstrate that this RNA sequence is able to bind directly to a trans-acting factor, Vg1RBP, which was previously shown to be involved in the localization of endodermal determinant factors. Loss-of-function analysis indicates that Vg1RBP is required for establishment of pancreatic fate within the endoderm, suggesting a synergism between Vg1RBP and Shirin in the embryo. This study argues for a central role of post-transcriptional mechanisms in establishing pancreatic fate, where a 3 UTR may recruit factors necessary for pancreatic development, and highlights an unknown embryological activity of Vg1RBP.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions
  • Animals
  • Base Sequence
  • Biomarkers / analysis
  • Blotting, Western
  • Cross-Linking Reagents / pharmacology
  • DNA, Complementary / chemistry
  • Embryo, Nonmammalian
  • GTPase-Activating Proteins / chemistry
  • GTPase-Activating Proteins / genetics
  • Glycoproteins / genetics
  • Glycoproteins / physiology*
  • In Situ Hybridization
  • Insulin / metabolism
  • Models, Biological
  • Molecular Sequence Data
  • Oligonucleotides, Antisense / pharmacology
  • Pancreas / embryology*
  • Point Mutation
  • Precipitin Tests
  • RNA-Binding Proteins / physiology*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transforming Growth Factor beta / genetics
  • Transforming Growth Factor beta / physiology*
  • Xenopus / embryology
  • Xenopus Proteins / chemistry
  • Xenopus Proteins / genetics


  • 3' Untranslated Regions
  • Biomarkers
  • Cross-Linking Reagents
  • DNA, Complementary
  • GDF1 protein, Xenopus
  • GTPase-Activating Proteins
  • Glycoproteins
  • Insulin
  • Oligonucleotides, Antisense
  • RNA-Binding Proteins
  • Transforming Growth Factor beta
  • Xenopus Proteins
  • shirin protein, Xenopus