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

• Published in: The EMBO journal 1996-08, Vol.15 (15), p.3943-3950
• Main Authors: Peverali, F.A, Isaksson, A, Papavassiliou, A.G, Plastina, P, Staszewski, L.M, Mlodzik, M, Bohmann, D
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Blotting, Western; Cell Differentiation; Conserved Sequence; DNA-binding proteins; Drosophila; Drosophila melanogaster; enzyme activity; MAP Kinase Kinase 1; mitogen activated protein kinase; Mitogen-Activated Protein Kinase Kinases; Molecular Sequence Data; mutants; Phosphorylation; Photoreceptor Cells, Invertebrate - cytology; photoreceptors; 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; Transcription Factors - metabolism
• ISSN: 0261-4189; 1460-2075
• DOI: 10.1002/j.1460-2075.1996.tb00768.x

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.