0000000000041120
AUTHOR
Collesano M
The nucleosome-remodeling ATPase ISWI is regulated by poly-ADP-ribosylation.
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…
Functional Interaction between ISWI and Covalent Modifiers of Chromatin
A MULTI-LAYER MODEL TO STUDY GENOME-SCALE POSITIONS OF NUCLEOSOMES
The positioning of nucleosomes along chromatin has been implicated in the regulation of gene expression in eukaryotic cells, because packaging DNA into nucleosomes affects sequence accessibility. In this paper we propose a new model (called MLM) for the identification of nucleosomes and linker regions across DNA, consisting in a thresholding technique based on cut-set conditions. For this purpose we have defined a method to generate synthetic microarray data fully inspired from the approach that has been used by Yuan et al. Results have shown a good recognition rate on synthetic data, moreover, the $MLM$ shows a good agreement with the recently published method based on Hidden Markov Model …
Flow Cytometry and Karyotype Analysis ofD. melanogasterEye Disc Cells
The developing Drosophila eye-antennal disc is a particularly suited system for the genetic and cellular studies of complex biological processes. Methods to analyze Drosophila eye discs by flow cytometry are mainly based on the dissociation of tissues with trypsin. Dissociation operated by trypsin is very effective, though it causes a lot of stress to live cells often compromising the use of treated cells for further analyses. Here, we report a method to produce dissociated eye-disc cells that retain cell-membrane markers and that can be used for flow cytometry and cytological analysis of mitotic chromosomes. The method described is a great complementing tool for the cellular characterizati…
A Dominant Modifiers Screen for Suppressors of ISWI Function
Functional Regulation of the Nucleosome Remodeling ATPase ISWI by PARP
The Nucleosome Remodeling ATPase ISWI is Regulated by poly-ADP-ribosylation
Functional Interaction between the Nucleosome Remodeling Factor ISWI and Covalent Modifiers of Chromatin
A genetic screen to identify ISWI antagonists in Drosophila melanogaster
A Genetic Screen for Dominant Modifiers of ISWI Reveals Functional Interactions with the SIN3A/RPD3 Complex
The nucleosome remodeling factor ISWI functionally interacts with an evolutionarily conserved network of cellular factors
Abstract ISWI is an evolutionarily conserved ATP-dependent chromatin remodeling factor playing central roles in DNA replication, RNA transcription, and chromosome organization. The variety of biological functions dependent on ISWI suggests that its activity could be highly regulated. Our group has previously isolated and characterized new cellular activities that positively regulate ISWI in Drosophila melanogaster. To identify factors that antagonize ISWI activity we developed a novel in vivo eye-based assay to screen for genetic suppressors of ISWI. Our screen revealed that ISWI interacts with an evolutionarily conserved network of cellular and nuclear factors that escaped previous genetic…
Loss of ISWI in Drosophila immaginal discs causes cell cycle defects
Genetic identification of a network of factors that functionally interact with the nucleosome remodeling ATPase ISWI.
Nucleosome remodeling and covalent modifications of histones play fundamental roles in chromatin structure and function. However, much remains to be learned about how the action of ATP-dependent chromatin remodeling factors and histone-modifying enzymes is coordinated to modulate chromatin organization and transcription. The evolutionarily conserved ATP-dependent chromatin-remodeling factor ISWI plays essential roles in chromosome organization, DNA replication, and transcription regulation. To gain insight into regulation and mechanism of action of ISWI, we conducted an unbiased genetic screen to identify factors with which it interacts in vivo. We found that ISWI interacts with a network o…