title: Digitor/dASCIZ Has Multiple Roles in Drosophila Development.
abstract: In this study we provide evidence that the spindle matrix protein Skeletor in Drosophila interacts with the human ASCIZ (also known as ATMIN and ZNF822) ortholog, Digitor/dASCIZ. This interaction was first detected in a yeast two-hybrid screen and subsequently confirmed by pull-down assays. We also confirm a previously documented function of Digitor/dASCIZ as a regulator of Dynein light chain/Cut up expression. Using transgenic expression of a mCitrine-labeled Digitor construct, we show that Digitor/dASCIZ is a nuclear protein that is localized to interband and developmental puff chromosomal regions during interphase but redistributes to the spindle region during mitosis. Its mitotic localization and physical interaction with Skeletor suggest the possibility that Digitor/dASCIZ plays a direct role in mitotic progression as a member of the spindle matrix complex. Furthermore, we have characterized a P-element insertion that is likely to be a true null Digitor/dASCIZ allele resulting in complete pupal lethality when homozygous, indicating that Digitor/dASCIZ is an essential gene. Phenotypic analysis of the mutant provided evidence that Digitor/dASCIZ plays critical roles in regulation of metamorphosis and organogenesis as well as in the DNA damage response. In the Digitor/dASCIZ null mutant larvae there was greatly elevated levels of γH2Av, indicating accumulation of DNA double-strand breaks. Furthermore, reduced levels of Digitor/dASCIZ decreased the resistance to paraquat-induced oxidative stress resulting in increased mortality in a stress test paradigm. We show that an early developmental consequence of the absence of Digitor/dASCIZ is reduced third instar larval brain size although overall larval development appeared otherwise normal at this stage. While Digitor/dASCIZ mutant larvae initiate pupation, all mutant pupae failed to eclose and exhibited various defects in metamorphosis such as impaired differentiation, incomplete disc eversion, and faulty apoptosis. Altogether we provide evidence that Digitor/dASCIZ is a nuclear protein that performs multiple roles in Drosophila larval and pupal development.
authors.affiliation: Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Saheli
authors.initials: S
authors.lastname: Sengupta
authors.affiliation: Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Uttama
authors.initials: U
authors.lastname: Rath
authors.affiliation: Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Changfu
authors.initials: C
authors.lastname: Yao
authors.affiliation: Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Michael
authors.initials: M
authors.lastname: Zavortink
authors.affiliation: Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.affiliation: Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Jack
authors.initials: J
authors.lastname: Girton
authors.affiliation: Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Kristen M
authors.initials: KM
authors.lastname: Johansen
authors.affiliation: Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Jørgen
authors.initials: J
authors.lastname: Johansen
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004249:DNA Damage; D004330:Drosophila / Q000254:growth & development / Q000378:metabolism*; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology / Q000378:metabolism; D015870:Gene Expression; D005838:Genotype; D018869:Heat-Shock Response; D006801:Humans; D007399:Interphase; D008675:Metamorphosis, Biological; D008938:Mitosis; D009154:Mutation; D034521:Nuclear Matrix-Associated Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D021381:Protein Transport; D015398:Signal Transduction; D013312:Stress, Physiological; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: C522841:ATMIN protein, human; D002868:Chromosomal Proteins, Non-Histone; D029721:Drosophila Proteins; D034521:Nuclear Matrix-Associated Proteins; D014157:Transcription Factors; C419556:skeletor protein, Drosophila