Search results for "drosophila"
showing 10 items of 782 documents
The nucleosome-remodeling ATPase ISWI is regulated by poly-ADP-ribosylation.
2008
ATP-dependent nucleosome-remodeling enzymes and covalent modifiers of chromatin set the functional state of chromatin. However, how these enzymatic activities are coordinated in the nucleus is largely unknown. We found that the evolutionary conserved nucleosome-remodeling ATPase ISWI and the poly-ADP-ribose polymerase PARP genetically interact. We present evidence showing that ISWI is target of poly-ADP-ribosylation. Poly-ADP-ribosylation counteracts ISWI function in vitro and in vivo. Our work suggests that ISWI is a physiological target of PARP and that poly-ADP-ribosylation can be a new, important post-translational modification regulating the activity of ATP-dependent nucleosome remodel…
Noncanonical RNAs from transcripts of the Drosophila muscleblind gene.
2006
It has become increasingly evident that eukaryotic cells produce RNA molecules from coding genes with constitutions other than those of typically spliced mRNA transcripts. Here we describe new cDNAs from the Drosophila melanogaster muscleblind (mbl ) locus that identify two such atypical RNA molecules: RNAs containing an incomplete exon 2 tandem repetition (mblE2E2#) or having exons with a different order compared to the corresponding genomic DNA (mblE2E3#E2#; exon scrambling). The existence of exon duplications and rearrangements in the genomic locus that might explain such cDNAs was ruled out by genomic Southern blotting and in silico analysis of the Drosophila genome sequence. The incomp…
Establishment of Polycomb silencing requires a transient interaction between PC and ESC
2001
Two distinct types of Polycomb complexes have been identified in flies and in vertebrates, one containing ESC and one containing PC. Using LexA fusions, we show that PC and ESC can establish silencing of a reporter gene but that each requires the presence of the other. In early embryonic extracts, we find PC transiently associated with ESC in a complex that includes EZ, PHO, PH, GAGA, and RPD3 but not PSC. In older embryos, PC is found in a complex including PH, PSC, GAGA, and RPD3, whereas ESC is in a separate complex including EZ, PHO, and RPD3.
Immunolocalization of Poly ADP-Ribose on Drosophila Polytene Chromosomes
2011
Poly ADP-ribosylation (PARylation) is a posttranslational protein modification catalyzed by poly -ADP-ribose polymerases (PARPs). Poly ADP-ribose metabolism is involved in a wide range of biological processes, such as maintenance of genome stability, transcriptional regulation, energy metabolism, and programed cell death. Recently, chromatin components, including histones, have been shown to be targets of PARylation. Unlike mammals, which have several PARP-encoded genes, the model organism Drosophila melanogaster has only one PARP gene, highly related to mammalian PARP1. These features make flies a great model system to study PARP biology. Commercially available antibodies recognizing this …
Variability of ecdysteroid-induced cell cycle alterations in Drosophila Kc sublines.
1987
. The cell cycle of two lines isolated from Drosophila Kc cells was followed by flow cytofluorometry and cell counting. The first line is the 8-9K clone which grew in a medium supplemented with 5% serum; the second, named subline Kc0, grew in a serum-free medium. The stationary phase is characterized by a G2 cell accumulation: 73% in the 8-9K clone and 50% in the Kc0 subline. When the medium was supplemented with the steroid moulting hormone 20-hydroxyecdysone, more than 90% of 8-9K cells and 65% of Kc0 cells were progressively arrested in G2. In the continuous presence of 20-hydroxyecdysone, most of the 8-9K cells remain G2-arrested; no massive G2 release into M was observed and only a few…
A high-throughput chemical screen in DJ-1β mutant flies identifies zaprinast as a potential Parkinson's disease treatment
2021
AbstractDopamine replacement represents the standard therapy for Parkinson’s disease (PD), a common, chronic, and incurable neurological disorder; however, this approach only treats the symptoms of this devastating disease. In the search for novel disease-modifying therapies that target other relevant molecular and cellular mechanisms, Drosophila has emerged as a valuable tool to study neurodegenerative diseases due to the presence of a complex central nervous system, the blood–brain barrier, and a similar neurotransmitter profile to humans. Human PD-related genes also display conservation in flies; DJ-1β is the fly ortholog of DJ-1, a gene for which mutations prompt early-onset recessive P…
Cisplatin-induced apoptosis in 43-3B and 27-1 cells defective in nucleotide excision repair
2001
Cisplatin is a highly potent cytotoxic and genotoxic agent used in the chemotherapy of various types of tumors. Its cytotoxic effect is supposed to be due to the induction of intra- and interstrand DNA cross-links which are repaired via the nucleotide excision repair (NER) pathway. Here, we elucidated the mechanism of cisplatin-induced cytotoxicity in mutants derived from CHO-9 cells defective in NER. We compared 43-3B and 27-1 cells deficient for ERCC1 and ERCC3, respectively, with the corresponding wild-type and ERCC1 complemented 43-3B cells. It is shown that cells defective in ERCC1 are more sensitive than cells defective in ERCC3 with regard to cisplatin-induced reproductive cell death…
The Role of Autophagy and Apoptosis During Embryo Development
2015
Programmed cell death (PCD) and cell survival are two sides of the same coin. Autopha‐ gy and apoptosis are crucial processes during embryo development of Invertebrates and Vertebrates organisms, as they are necessary for the formation of a new organism, start‐ ing from a fertilized egg. Fertilization triggers cell remodeling from each gamete to a toti‐ potent zygote. During embryogenesis, the cells undergo various processes, thus allowing the transformation of the embryo into an adult organism. In particular, cells require the appropriate tools to suddenly modify their morphology and protein content in order to respond to intrinsic and external stimuli. Autophagy and apoptosis are involved…
Cell cycle independent role of Cyclin E during neural cell fate specification in Drosophila is mediated by its regulation of Prospero function
2009
AbstractDuring development, neural progenitor cells or neuroblasts generate a great intra- and inter-segmental diversity of neuronal and glial cell types in the nervous system. In thoracic segments of the embryonic central nervous system of Drosophila, the neuroblast NB6-4t undergoes an asymmetric first division to generate a neuronal and a glial sublineage, while abdominal NB6-4a divides once symmetrically to generate only 2 glial cells. We had earlier reported a critical function for the G1 cyclin, CyclinE (CycE) in regulating asymmetric cell division in NB6-4t. Here we show that (i) this function of CycE is independent of its role in cell cycle regulation and (ii) the two functions are m…
Bishistidyl heme hexacoordination, a key structural property in Drosophila melanogaster hemoglobin
2005
Hemoglobins at high concentration have been isolated long ago from some insect larvae living in hypoxic environments. Conversely, a monomeric hemoglobin has been discovered recently in the fruit fly Drosophila melanogaster as intracellular protein expressed both in larvae and in the adult fly. Such a finding indicates that the oxygen supply in insects may be more complex than previously thought, relying not only on O2 diffusion through the tubular tracheal system, but also on carrier-mediated transport and storage. We present here the crystal structure of recombinant D. melanogaster hemoglobin at 1.20 A resolution. Spectroscopic data show that the protein displays a hexacoordinated heme, wh…