title: The complex containing Drosophila Myb and RB/E2F2 regulates cytokinesis in a histone H2Av-dependent manner.
abstract: In Drosophila, mutation of the oncogene Myb reduced the expression of mitotic genes, such as polo and ial, and caused multiple mitotic defects, including disrupted chromosome condensation and abnormal spindles. We now show that binucleate cells, the hallmark phenotype of cytokinesis failure, accumulate in Myb-null ovarian follicle cell and wing disc epithelia. Myb functions as an activator in the generally repressive Drosophila RBF, E2F2, and Myb (dREAM)/Myb-MuvB complex. Absence of the dREAM subunit Mip130 or E2F2 suppressed the Myb-null cytokinesis defect. Therefore, we used Myb-null binucleate cells as a quantitative phenotypic readout of transcriptional repression by the dREAM complex. In the absence of Myb, the complex was sensitive to the dose of the subunits E2F2, Mip120, Caf1, and Lin-52 but not Mip130 or Mip40. Surprisingly, reduction of the dose of His2Av/H2A.z also suppressed the Myb-null binucleate cell phenotype, suggesting a novel role for this variant histone in transcriptional repression by the dREAM complex.
authors: Department of Genetics, Stanford University, Stanford, California, USA.
authors: Heather
authors: H
authors: DeBruhl
authors: Hong
authors: H
authors: Wen
authors: Joseph S
authors: JS
authors: Lipsick
mesh_terms: D000818:Animals; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D048749:Cytokinesis; D004330:Drosophila / Q000166:cytology* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D050703:E2F2 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D005260:Female; D017353:Gene Deletion; D005786:Gene Expression Regulation; D006657:Histones / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D006080:Ovarian Follicle / Q000166:cytology / Q000378:metabolism; D010641:Phenotype; D020598:Proto-Oncogene Proteins c-myb / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016160:Retinoblastoma Protein / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D015533:Transcriptional Activation; D014921:Wings, Animal / Q000166:cytology / Q000254:growth & development / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D029721:Drosophila Proteins; D050703:E2F2 Transcription Factor; C115434:E2f2 protein, Drosophila; D006657:Histones; C467519:Myb protein, Drosophila; D020598:Proto-Oncogene Proteins c-myb; C099965:Rbf protein, Drosophila; D016160:Retinoblastoma Protein; D014157:Transcription Factors