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 remodelers

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 of factors that escaped detection in previous biochemical analyses, including the Sin3A gene. The Sin3A protein and the histone deacetylase Rpd3 are part of a conserved histone deacetylase complex involved in transcriptional repression. ISWI and the Sin3A/Rpd3 complex co-localize at specific chromosome domains. Loss of ISWI activity causes a reduction in the binding of the Sin3A/Rpd3 complex to chromatin. Biochemical analysis showed that the ISWI physically interacts with the histone deacetylase activity of the Sin3A/Rpd3 complex. Consistent with these findings, the acetylation of histone H4 is altered when ISWI activity is perturbed in vivo. These findings suggest that ISWI associates with the Sin3A/Rpd3 complex to support its function in vivo

Flow Cytometry and Karyotype Analysis of D.melanogaster Eye 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 characterization of phenotypes resulting from classic clonal and miss-expression approaches in the Drosophila eye. DISTRIBUTE. © 2007 Landes Bioscience

Esperienza di team building: costruzione di una squadra efficace in un Corso di laurea in Igiene Dentale

Obiettivi: far conoscere in modo più profondo, aumentare la fiducia nei propri colleghi, migliorare il livello di collaborazione, stimolare la creatività, favorire la comunicazione tra studenti e tutor e studenti e studenti di un Corso di Laurea in Igiene Dentale. Materiali e metodi: realizzazione di una giornata di Team Building in un setting outdoor. Risultati: 32 studenti, tutor e Coordinatore didattico nel Parco del Castello di Pavia si sono messi in gioco parlando di sé, partecipando a team game e fasi di debriefing. Conclusioni: l’esperienza formativa ha permesso di trasformare un gruppo di studenti e tutor in una squadra.Objectives: Aims of the study were improving acquaintance; confidence, cooperation, communication, creativity, out of all tutors and students, and students and students of Dental Hygiene Degree Program. Materials and methods: realize a Team Building outdoor experience. Results: 32 students, tutors and the Coordinator in the Pavia Castle Park put themselves in the game speaking of themselves, taking part in team games debriefing. Conclusions: the teaching experience allowed to transform a tutor and student group in a high-performance team

Mezzi di prevenzione della carie in ortodonzia

Poiché in campo odontoiatrico sono in atto diverse metodiche di prevenzione, basate principalmente sulla remineralizzazione della superficie dentale offesa dopo il trattamento, in questo lavoro abbiamo voluto revisionare la letteratura disponibile per conoscere la loro reale efficacia durante il trattamento ortodontico. Com’è noto l’utilizzo di apparecchi comporta spesso difficoltà nel mantenimento di un’adeguata igiene orale. Per questo motivo nei pazienti ortodontici si rileva frequentemente un aumento di accumulo di placca e, di conseguenza, dell’incidenza di demineralizzazione dello smalto dovuta agli acidi organici derivati dai batteri contenuti nella placca stessa

Esperienza di team building: costruzione di una squadra efficace in un Corso di laurea in Igiene Dentale

Obiettivi: far conoscere in modo più profondo, aumentare la fiducia nei propri colleghi, migliorare il livello di collaborazione, stimolare la creatività, favorire la comunicazione tra studenti e tutor e studenti e studenti di un Corso di Laurea in Igiene Dentale. Materiali e metodi: realizzazione di una giornata di Team Building in un setting outdoor. Risultati: 32 studenti, tutor e Coordinatore didattico nel Parco del Castello di Pavia si sono messi in gioco parlando di sé, partecipando a team game e fasi di debriefing. Conclusioni: l’esperienza formativa ha permesso di trasformare un gruppo di studenti e tutor in una squadra