PT  - JOURNAL ARTICLE
AU  - Roman Renger
AU  - Jose A. Morin
AU  - Regis Lemaitre
AU  - Martine Ruer-Gruss
AU  - Frank Jülicher
AU  - Andreas Hermann
AU  - Stephan W. Grill
TI  - Co-condensation of proteins with single- and double-stranded DNA
AID  - 10.1101/2021.03.17.435834
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.03.17.435834
4099  - http://biorxiv.org/content/early/2021/03/17/2021.03.17.435834.short
4100  - http://biorxiv.org/content/early/2021/03/17/2021.03.17.435834.full
AB  - Biomolecular condensates provide distinct compartments that can localize and organize biochemistry inside cells. Recent evidence suggests that condensate formation is prevalent in the cell nucleus and associated with a variety of important processes ranging from transcriptional regulation to DNA repair. To understand how different components of the nucleus interact during condensate formation is an important challenge. In particular, the physics of co-condensation of proteins together with nucleic acids remains elusive. Here, we use optical tweezers to study how the prototypical prion-like protein Fused-in-Sarcoma (FUS) forms liquid-like assemblies in vitro, by co-condensing together with individual single- and double stranded DNA molecules. Through progressive DNA unpeeling, buffer exchange and direct force measurements, we show that FUS adsorbing in a single layer on DNA effectively generates a sticky FUS-DNA polymer that can collapse to form a liquid-like FUS-DNA co-condensate. For double-stranded DNA, this condensation occurs at constant DNA tension which is a signature of a phase separation phenomenon. We suggest that co-condensation mediated by protein adsorption on nucleic acids is an important mechanism for forming intracellular compartments.Competing Interest StatementThe authors have declared no competing interest.