Shaggy/GSK-3beta kinase localizes to the centrosome and to specialized cytoskeletal structures in Drosophila.
The assembly of a functional bipolar mitotic spindle requires an exquisite regulation of microtubule behavior in time and space. To characterize new elements of this machinery we carried out a GFP based "protein trap" screen and selected fusion proteins which localized to the spindle apparatus. By this method we identified Shaggy, the Drosophila homologue of glycogen synthase kinase-3beta (GSK-3beta), as a component of centrosomes. GSK-3beta acting in the Wingless signaling pathway is involved in a vast range of developmental processes, from pattern formation to cell-fate specification, and is a key factor for cell proliferation in most animals. We exploited our Shaggy::GFP Drosophila line to analyze the subcellular localizations of GSK-3beta/Shaggy and shed light on its multiple roles during embryogenesis. We found that Shaggy becomes enriched transiently in a variety of specialized cytoskeletal structures of the embryo, including centrosomes throughout mitosis, suggesting that this kinase is involved in the regulation of many aspects of the cytoskeleton function.
Biologie du Développement, UMR 7009 CNRS / Université Pierre et Marie Curie, Observatoire Océanologique, Villefranche-sur-mer, France.
Yves
Y
Bobinnec
Xavier
X
Morin
Alain
A
Debec
D000818:Animals; D049109:Cell Proliferation; D018385:Centrosome / Q000201:enzymology* / Q000502:physiology / Q000648:ultrastructure; D003599:Cytoskeleton / Q000201:enzymology* / Q000502:physiology / Q000648:ultrastructure; D004330:Drosophila / Q000196:embryology / Q000201:enzymology* / Q000235:genetics / Q000648:ultrastructure; D029721:Drosophila Proteins / Q000378:metabolism*; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D008941:Spindle Apparatus / Q000201:enzymology* / Q000502:physiology / Q000648:ultrastructure; D051155:Wnt1 Protein
D029721:Drosophila Proteins; D011518:Proto-Oncogene Proteins; D051155:Wnt1 Protein; C074622:wg protein, Drosophila; D049452:Green Fluorescent Proteins; C080335:Sgg protein, Drosophila; D038362:Glycogen Synthase Kinase 3