Phosphorylation of Drosophila Jun by the MAP kinase rolled regulates photoreceptor differentiation.
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.
Peverali
F A
FA
EMBL, Meyerhofstrasse 1, Postfach 102209, 69012 Heidelberg, Germany.
Isaksson
A
A
Papavassiliou
A G
AG
Plastina
P
P
Staszewski
L M
LM
Mlodzik
M
M
Bohmann
D
D
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation; D017124:Conserved Sequence; D004330:Drosophila; D048369:MAP Kinase Kinase 1; D020929:Mitogen-Activated Protein Kinase Kinases; D008969:Molecular Sequence Data; D010766:Phosphorylation; D017956:Photoreceptor Cells, Invertebrate / Q000166:cytology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism
D016755:Proto-Oncogene Proteins c-jun; D014157:Transcription Factors; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D048369:MAP Kinase Kinase 1; D020929:Mitogen-Activated Protein Kinase Kinases