Partenaires
Rechercher
Accueil du site > Animations Scientifiques > Séminaires 2011 > Maïté Coppey — Evidence of spatio-temporal fluctuations of supranucleosomal state regulating accessibility of bromodomain to acetylated H4 in living cells by high-resolution FLIM
Maïté Coppey — Evidence of spatio-temporal fluctuations of supranucleosomal state regulating accessibility of bromodomain to acetylated H4 in living cells by high-resolution FLIM
Speaker :
Maïté Coppey, Institut Jacques Monod, Paris
When :
Wednesday 26 January at 11am
Where :
C023 (RDC LR6 côté Centre Blaise Pascal)
Title :
Evidence of spatio-temporal fluctuations of supranucleosomal state regulating accessibility of bromodomain to acetylated H4 in living cells by high-resolution FLIM
Abstract :
We unveiled spatio-temporal fluctuations of the fluorescence lifetime of EGFP-histone H4 in living cells (HEK 293) by using fast time-lapse FLIM measurement and two-photon excitation. We showed that these fluctuations are likely due to the variations of the microenvironment of the EGFP-H4 incorporated in chromatin and thus reflect the variations of a supra-nucleosomal state of chromatin domains of about 0.6 micron of diameter. Interestingly, the interaction between the double bromodomain of TAFII250 and the acetylated histone H4 exhibit similar spatio-temporal fluctuations. Furthermore, no interactions can be detected when chromatin is shifted to a “close” supra-nucleosomal state characterized by short fluorescence lifetime of EGFP-H4, after ATP depletion. A detailed pixel by pixel analysis over 100 time-lapse FLIM images revealed the existence of a correlation between the temporal mean value and the amplitude of the fluctuations of fluorescence lifetime of EGFP-H4. Spatial mapping of this correlation unveiled a more dynamical chromatin at the nucleus periphery. We propose that these fluctuations of supra-nucleosomal state would modulate the accessibility of protein factors to nucleosomes and thus likely correspond to a switch between “open” and “close” states of chromatin domain.
Dans la même rubrique :
- Loïc Le Goff — The mechanics of a growing epithelium
- Marie-Noëlle Prioleau — Control of the spatio-temporal program of DNA replication in vertebrates
- Véronique Rosilio — Molecular organized films of lipids, proteins and amphiphilic polymers : Application to innovative pharmaceutical systems.
- Saadi Khochbin — Molecular basis of post-meiotic male genome reprogramming : essential role for histone hyperacetylation and histone variants
- Nicolas Lartillot — Modèles probabilistes et chaînes de Markov Monte Carlo en évolution moléculaire.
- Hélène Delanoë-Ayari — Déplacement de cellules en 2 et 3 dimensions
- Jean-Paul Rieu — Collective migration in Dictyostelium
- André Verdel — Connexions entre ARN interférence (RNAi) et chromatine chez S. pombe
- Laurent Bonneviot — Approche bio-inspirée de l’Ingénierie moléculaire de surface en milieu confiné et conception de catalyseurs hétérogènes
- Claire Francastel — Hypométhylation, transcription des régions centromériques et pathologies
- Didier Boturyn — Conception de Vecteurs Peptidiques : Applications Thérapeutiques et Diagnostiques
- Laurent Bonneviot — reprogrammé le 15 juin
- Charles Auffray, Laurent Nottale — Systems Biology and Scale Relativity
- Aurélien Bancaud — Micro et nanosystèmes fluidique pour l’étude des chromosomes
- Pascale Lesage — Stress induced coregulation of Ty1 retrotransposon sense and antisense transcription
- Peter Meister — Putting things in place : sequences and signals for genome nuclear organization
- François Parcy — Can genomic sequences help us to understand flower evolution ?
- Manlio Vinciguerra — SIRT1 signaling and epigenetics during cellular stress
- Bertrand Mollereau — Modeling Neurodegenerative diseases in Drosophila
- Giovanni Sena — Plant Organs Regeneration : Measuring Self-Organization
