title: Rapsynoid/partner of inscuteable controls asymmetric division of larval neuroblasts in Drosophila.
abstract: Asymmetric cell division generates daughter cells with different developmental fates. In Drosophila neuroblasts, asymmetric divisions are characterized by (1) a difference in size between the two daughter cells and (2) an asymmetric distribution of cell fate determinants, including Prospero and Numb, between the two daughter cells. In embryonic neuroblasts, the asymmetric localization of cell fate determinants is under the control of the protein Inscuteable (Insc), which is itself localized asymmetrically as an apical crescent. Here, we describe a new Drosophila protein, Rapsynoid (Raps), which interacts in a two-hybrid assay with the signal transduction protein Galpha(i). We show that Raps is localized asymmetrically in dividing larval neuroblasts and colocalizes with Insc. Moreover, in raps mutants, the asymmetric divisions of neuroblasts are altered: (1) Insc is no longer asymmetrically localized in the dividing neuroblast; and (2) the neuroblast division produces two daughter cells of similar sizes. However, the morphologically symmetrical divisions of raps neuroblasts still lead to daughter cells with different fates, as shown by differences in gene expression. Our data show that Raps is a novel protein involved in the control of asymmetric divisions of neuroblasts.
authors.affiliation: Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom. parment@ccipe.montp.inserm.fr
authors.forename: M L
authors.initials: ML
authors.lastname: Parmentier
authors.forename: D
authors.initials: D
authors.lastname: Woods
authors.forename: S
authors.initials: S
authors.lastname: Greig
authors.forename: P G
authors.initials: PG
authors.lastname: Phan
authors.forename: A
authors.initials: A
authors.lastname: Radovic
authors.forename: P
authors.initials: P
authors.lastname: Bryant
authors.forename: C J
authors.initials: CJ
authors.lastname: O'Kane
mesh_terms: D020816:Amino Acid Motifs / Q000502:physiology; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D016764:Cell Polarity / Q000502:physiology; D048429:Cell Size / Q000502:physiology; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D051960:GTP-Binding Protein alpha Subunit, Gi2; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000378:metabolism; D015870:Gene Expression; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D007814:Larva; D008969:Molecular Sequence Data; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009479:Neuropeptides; D017434:Protein Structure, Tertiary / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D020449:Repetitive Sequences, Amino Acid / Q000502:physiology; D017386:Sequence Homology, Amino Acid; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D029721:Drosophila Proteins; C102754:GPSM2 protein, human; D019476:Insect Proteins; D047908:Intracellular Signaling Peptides and Proteins; C107613:Mira protein, Drosophila; D009479:Neuropeptides; C405164:Pins protein, Drosophila; D011518:Proto-Oncogene Proteins; C098678:insc protein, Drosophila; D051960:GTP-Binding Protein alpha Subunit, Gi2; D019206:GTP-Binding Protein alpha Subunits, Gi-Go