Projektbeschreibung
Von Chromatinaktivitäten im Mikrometerbereich zu neuen Eigenschaften auf Makroebene
Die riesige Menge an DNS in einer Zelle ist ähnlich wie Perlen auf dem fadenähnlichen Chromatinkomplex um Proteine gewickelt. Es mehren sich die Hinweise darauf, dass die neu eintretenden Materialeigenschaften des Chromatins wesentliche Kernprozesse regulieren. Die Charakterisierung dieser Eigenschaften gestaltete sich bisher schwierig, da es In-vitro-Experimenten an der Komplexität der Zellmaschinerie mangelt, während Studien an intakten Zellen keinen problemlosen Zugang zur kleinmaßstäblichen Dynamik gewähren. Das EU-finanzierte Projekt SynthNuc wird nun diese Wissenslücke mit Eiextrakten von Xenopus laevis und synthetischen Kernen, die aus vorgefertigten DNS-Sequenzen bestehen, schließen. Hochtechnisierte Versuchsverfahren werden Aufschluss darüber geben, wie kollektive Chromatinaktivitäten im kleinen Maßstab die großmaßstäblichen Materialeigenschaften des Chromatins erzeugen.
Ziel
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.
Wissenschaftliches Gebiet
Schlüsselbegriffe
Programm/Programme
- HORIZON.1.1 - European Research Council (ERC) Main Programme
Thema/Themen
Finanzierungsplan
HORIZON-ERC - HORIZON ERC GrantsGastgebende Einrichtung
01069 Dresden
Deutschland