Descrizione del progetto
Dalle attività su microscala della cromatina alle proprietà emergenti su macroscala
L’enorme quantità di DNA in una cellula è avvolto attorno alle proteine, come perline su un filo, in un complesso chiamato cromatina. Prove sempre più numerose indicano che le proprietà dei materiali emergenti della cromatina regolano i processi nucleari essenziali. La caratterizzazione di queste proprietà non è stata chiarita, in quanto agli studi in vitro manca la complessità dell’apparato cellulare, mentre gli studi su cellule intatte non possono accedere facilmente alle dinamiche su piccola scala. Il progetto SynthNuc, finanziato dall’UE, colmerà questo divario di scala con estratti delle uova di Xenopus laevis e nuclei sintetici composti da sequenze di DNA pre-ingegnerizzate. Alcune tecniche sperimentali ad alta tecnologia faranno luce su come le attività collettive su piccola scala della cromatina diano origine alle sue proprietà materiali su larga scala.
Obiettivo
The main aim of this proposal is to resolve how the physics of molecular-scale activities result in the emergent material properties of chromatin and how those contribute to chromatin organization and function. Mounting evidence suggests that the material properties of chromatin regulate essential nuclear processes. Chromatin has been studied with two disconnected approaches; pure in vitro studies, perfectly suited for careful biophysical measurements on single DNA molecules but lacking the complexity of a cell, or intact cell measurements, with limited access to measure material properties and small-scale chromatin dynamics. The physical properties of chromatin, however, are emergent and result from the molecular activities that are in turn regulated by those properties. As a consequence, it is crucial to establish new experimental assays that connect these two scales and levels of complexity. Here, I will bridge the gap in scales and biochemistry between pure in vitro assays and measurements in intact cells by reconstituting chromatin processes in Xenopus laevis egg extracts across scales. I will combine quantitative microscopy, optical tweezer measurements, and theory to biophysically characterize the self-organization of protein-DNA co-condensation and loop extrusion and single chromatin molecules of increasing complexity. To bridge the microscopic and the macroscopic scales, I will assemble synthetic nuclei made of pre-engineered DNA sequences, which allows for exquisite control of DNA length, amount, and chromatin activities. In combination with microrheology, micropipette aspiration, and magnetic tweezers, I will unravel how the collective behavior of chromatin activities gives rise to the emergence of large-scale material properties of chromatin. This project will provide a physical description of the material state of chromatin across scales and contribute to reveal the basic physical principles that govern nuclear organization and function.
Campo scientifico
Parole chiave
Programma(i)
- HORIZON.1.1 - European Research Council (ERC) Main Programme
Argomento(i)
Meccanismo di finanziamento
HORIZON-ERC - HORIZON ERC GrantsIstituzione ospitante
01069 Dresden
Germania