cdc2 links the Drosophila cell cycle and asymmetric division machineries.
Asymmetric cell divisions can be mediated by the preferential segregation of cell-fate determinants into one of two sibling daughters. In Drosophila neural progenitors, Inscuteable, Partner of Inscuteable and Bazooka localize as an apical cortical complex at interphase, which directs the apical-basal orientation of the mitotic spindle as well as the basal/cortical localization of the cell-fate determinants Numb and/or Prospero during mitosis. Although localization of these proteins shows dependence on the cell cycle, the involvement of cell-cycle components in asymmetric divisions has not been demonstrated. Here we show that neural progenitor asymmetric divisions require the cell-cycle regulator cdc2. By attenuating Drosophila cdc2 function without blocking mitosis, normally asymmetric progenitor divisions become defective, failing to correctly localize asymmetric components during mitosis and/or to resolve distinct sibling fates. cdc2 is not necessary for initiating apical complex formation during interphase; however, maintaining the asymmetric localization of the apical components during mitosis requires Cdc2/B-type cyclin complexes. Our findings link cdc2 with asymmetric divisions, and explain why the asymmetric localization of molecules like Inscuteable show cell-cycle dependence.
Institute of Molecular and Cell Biology, Singapore.
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Tio
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Udolph
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Yang
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Chia
D000818:Animals; D016203:CDC2 Protein Kinase / Q000235:genetics / Q000502:physiology*; D002352:Carrier Proteins / Q000502:physiology; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000502:physiology; D002455:Cell Division; D002490:Central Nervous System / Q000166:cytology; D016213:Cyclins / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000502:physiology; D004330:Drosophila; D029721:Drosophila Proteins; D005838:Genotype; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000502:physiology; D009479:Neuropeptides; D009687:Nuclear Proteins / Q000502:physiology; D010641:Phenotype; D010766:Phosphorylation; D014157:Transcription Factors
D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D016213:Cyclins; D003598:Cytoskeletal Proteins; D029721:Drosophila Proteins; C107613:Mira protein, Drosophila; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; D009687:Nuclear Proteins; C115164:PON protein, Drosophila; D014157:Transcription Factors; C098678:insc protein, Drosophila; C073099:pros protein, Drosophila; D016203:CDC2 Protein Kinase