miranda localizes staufen and prospero asymmetrically in mitotic neuroblasts and epithelial cells in early Drosophila embryogenesis.
When neuroblasts divide, prospero protein and mRNA segregate asymmetrically into the daughter neuroblast and sibling ganglion mother cell. miranda is known to localize prospero protein to the basal cell cortex of neuroblasts while the staufen RNA-binding protein mediates prospero mRNA localization. Here we show that miranda is required for asymmetric staufen localization in neuroblasts. Analyses using miranda mutants reveal that prospero and staufen interact with miranda under the same cell-cycle-dependent control. miranda thus acts to partition both prospero protein and mRNA. Furthermore, miranda localizes prospero and staufen to the basolateral cortex in dividing epithelial cells, which express the three proteins prior to neurogenesis. Our observations suggest that the epithelial cell and neuroblast (both of epithelial origin) share the same molecular machinery for creating cellular asymmetry.
Matsuzaki
F
F
Department of Molecular Genetics, National Institute of Neuroscience, NCNP, Kodaira, Tokyo 187, Japan. fumio@ncnaxp.ncnp.go.jp.
Ohshiro
T
T
Ikeshima-Kataoka
H
H
Izumi
H
H
D000483:Alleles; D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics / Q000502:physiology*; D016764:Cell Polarity / Q000235:genetics; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000166:cytology / Q000196:embryology* / Q000235:genetics; D004475:Ectoderm / Q000166:cytology; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D017952:Ganglia, Invertebrate / Q000166:cytology; D017344:Genes, Insect; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008938:Mitosis / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D017384:Sequence Deletion; D013234:Stem Cells; D014157:Transcription Factors
D018797:Cell Cycle Proteins; D029721:Drosophila Proteins; C107613:Mira protein, Drosophila; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; D014157:Transcription Factors; C073099:pros protein, Drosophila; C069927:stau protein, Drosophila