Phosphorylation of Drosophila Jun by the MAP kinase rolled regulates photoreceptor differentiation

EMBO J. 1996 Aug 1;15(15):3943-50.


Drosophila Jun (D-Jun) is a nuclear component of the receptor tyrosine kinase/Ras signal transduction pathway which triggers photoreceptor differentiation during eye development. Here we show that D-Jun is a substrate for the ERK-related Drosophila MAP kinase Rolled, which has previously been shown to be a part of this pathway. A D-Jun mutant that carries alanines in place of the Rolled phosphorylation sites acts as a dominant suppressor of photoreceptor cell fate if expressed in the eye imaginal disc. In contrast, a mutant in which the phosphorylation sites are replaced by phosphate-mimetic Asp residues, as well as a VP16-D-Jun fusion protein, can promote photoreceptor differentiation. These data implicate Jun phosphorylation in the choice between neuronal and non-neuronal fate during Drosophila eye development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Blotting, Western
  • Cell Differentiation
  • Conserved Sequence
  • Drosophila
  • MAP Kinase Kinase 1
  • Mitogen-Activated Protein Kinase Kinases*
  • Molecular Sequence Data
  • Phosphorylation
  • Photoreceptor Cells, Invertebrate / cytology*
  • Protein-Serine-Threonine Kinases / metabolism*
  • Protein-Tyrosine Kinases / metabolism*
  • Proto-Oncogene Proteins c-jun / genetics
  • Proto-Oncogene Proteins c-jun / metabolism*
  • Signal Transduction
  • Transcription Factors / metabolism


  • Proto-Oncogene Proteins c-jun
  • Transcription Factors
  • Protein-Tyrosine Kinases
  • Protein-Serine-Threonine Kinases
  • MAP Kinase Kinase 1
  • Mitogen-Activated Protein Kinase Kinases