Capillary forces and the force response of condensates (A5)

The goal of of A5 is to understand how condensates respond to mechanical forces and how condensate-mediated capillary forces influence the shape and organization of biopolymers.

Biomolecular condensates are mostly considered as special biochemical environments. However, due to their tendency to minimize their interfacial area, condensates generate relevant capillary forces that can bundle and bend soft cellular structures. Recently, the Jahnel and Grill labs have explored the mechanical effects of condensates on various biopolymers such as nucleic acids and cytoskeletal filaments. In collaboration with the Hyman and Jülicher groups, the Grill group has discovered the prewetting and co-condensation of transcription factors on DNA and that condensates can bundle DNA. Furthermore, in collaboration with the Jülicher group, the Grill group has discovered a condensate dynamic instability that is crucial to establishing the actin cell cortex during early nematode development. In collaboration with the Alberti and Brugués groups, the Jahnel group has discovered that a DNA damage repair condensate can bridge fragments of broken DNA and hold them together. Preliminary data from the Jahnel lab show that condensates of RNA-binding proteins important for mRNA transport along axons affect not only the folding dynamics of long regulatory RNAs but also can wet, bundle, and bend microtubules (collaboration with Diez group at B CUBE, TU Dresden). Finally, preliminary data from the Grill lab demonstrate shape changes of cortical condensates are likely driven by condensate surface tension and identify a mechanical role of DNA-binding proteins during the assembly of the nuclear periphery (Collaboration with von Appen group at MPI-CBG). Despite this progress, the rich interplay between condensate interfacial energies, condensate-polymer interaction energies, and biopolymer bending energies has not been systematically studied and remains poorly understood.

1) How do condensates respond to mechanical forces and exert capillary forces on various cellular structures?

2) Can we predict the mechanical condensate-polymer behavior?

3) How to measure the interfacial properties and interaction energies of condensates and their substrates?

Regulatory RNA folding in and around condensates

The PhD students will be trained in in soft matter physics concepts, single-molecule experiments, protein and nucleic acid molecular biology methods, data and image analysis methods and state-of-the-art instrumentation such as optical tweezers and light-sheet microscopy.

• Candidates have a Masters degree in physics, biology or related fields
• Candidates should have a sound basis in (theoretical) biophysics, polymer science, quantitative biology, or closely related fields.
• Experience in microscopy and protein isolation methods are expected

We are currently recruiting the first cohort of motivated doctoral candidates to join our research training group “RTG 3120 Biomolecular Condensates”. If you are a potential applicant, register and complete the following form . If you have questions about the research topic, then email the project supervisor >