The viscoelastic properties of chromatin and the nucleoplasm revealed by scale-dependent protein mobility

• Verfasst von: Erdel, Fabian [VerfasserIn]
• Verfasst von: Baum, Michael [VerfasserIn]
• Verfasst von: Rippe, Karsten [VerfasserIn]
• Titel: The viscoelastic properties of chromatin and the nucleoplasm revealed by scale-dependent protein mobility
• Verf.angabe: Fabian Erdel, Michael Baum and Karsten Rippe
• E-Jahr: 2015
• Jahr: 7 January 2015
• Umfang: 13 S.
• Fussnoten: Gesehen am 16.07.2020
• Titel Quelle: Enthalten in: Journal of physics / Condensed matter
• Ort Quelle: Bristol : IOP Publ., 1989
• Jahr Quelle: 2015
• Band/Heft Quelle: 27(2015,6) Artikel-Nummer 064115, 13 Seiten
• ISSN Quelle: 1361-648X
• DOI: doi:10.1088/0953-8984/27/6/064115
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1724963732

Abstract

The eukaryotic cell nucleus harbours the DNA genome that is organized in a dynamic chromatin network and embedded in a viscous crowded fluid. This environment directly affects enzymatic reactions and target search processes that access the DNA sequence information. However, its physical properties as a reaction medium are poorly understood. Here, we exploit mobility measurements of differently sized inert green fluorescent tracer proteins to characterize the viscoelastic properties of the nuclear interior of a living human cell. We find that it resembles a viscous fluid on small and large scales but appears viscoelastic on intermediate scales that change with protein size. Our results are consistent with simulations of diffusion through polymers and suggest that chromatin forms a random obstacle network rather than a self-similar structure with fixed fractal dimensions. By calculating how long molecules remember their previous position in dependence on their size, we evaluate how the nuclear environment affects search processes of chromatin targets.