Tribbles coordinates mitosis and morphogenesis in Drosophila by regulating string/CDC25 proteolysis.
Morphogenesis and cell differentiation in multicellular organisms often require accurate control of cell divisions. We show that a novel cell cycle regulator, tribbles, is critical for this control during Drosophila development. During oogenesis, the level of tribbles affects the number of germ cell divisions as well as oocyte determination. The mesoderm anlage enters mitosis prematurely in tribbles mutant embryos, leading to gastrulation defects. We show that Tribbles acts by specifically inducing degradation of the CDC25 mitotic activators String and Twine via the proteosome pathway. By regulating CDC25, Tribbles serves to coordinate entry into mitosis with morphogenesis and cell fate determination.
Mata
J
J
Developmental Biology Programme, European Molecular Biology Laboratory, Heidelberg, Germany.
Curado
S
S
Ephrussi
A
A
Rørth
P
P
D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D004330:Drosophila / Q000196:embryology / Q000502:physiology*; D029721:Drosophila Proteins; D005260:Female; D016195:G2 Phase; D017344:Genes, Insect; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D008938:Mitosis / Q000502:physiology*; D009024:Morphogenesis; D010053:Ovary / Q000196:embryology; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D017027:Protein Tyrosine Phosphatases; D014162:Transfection; D020687:cdc25 Phosphatases / Q000378:metabolism
D018797:Cell Cycle Proteins; D029721:Drosophila Proteins; D019476:Insect Proteins; C410505:trbl protein, Drosophila; D017346:Protein Serine-Threonine Kinases; D010749:Phosphoprotein Phosphatases; D017027:Protein Tyrosine Phosphatases; D020687:cdc25 Phosphatases; C059217:stg protein, Drosophila