2. Academic Validation
  3. Pre-assembly of biomolecular condensate seeds drives RSV replication

Pre-assembly of biomolecular condensate seeds drives RSV replication

  • Nature. 2026 Jan 28. doi: 10.1038/s41586-025-10071-5.
Dhanushika Ratnayake 1,  Marie Galloux # 2,  Sanne Boersma # 1,  Marko Noerenberg # 3 4,  Christina Sizun 5,  Carlos Sacristan 1,  Julien Sourimant 2,  Anke J Lakerveld 6,  Anne T Gelderloos 6,  Leonie Apperloo 1,  Yana Demyanenko 7,  Matthijs J D Baars 1,  Rupa Banerjee 1,  Birgit Dreier 8,  Sven Furler 8,  Natalie I Mazur 9 10,  Louis J Bont 9 10 11,  Shabaz Mohammed 4 7 12,  Andreas Plückthun 8,  Jean-François Éléouët 2,  Geert J P L Kops 1,  Alfredo Castello 3 4,  Puck B van Kasteren 6,  Marie-Anne Rameix-Welti 13 14 15,  Marvin E Tanenbaum 16 17
Affiliations

Affiliations

  • 1 Oncode Institute, Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, Utrecht, the Netherlands.
  • 2 Université Paris-Saclay, INRAE, UVSQ, VIM, Jouy-en-Josas, France.
  • 3 MRC-University of Glasgow Centre for Virus Research, Glasgow, UK.
  • 4 Department of Biochemistry, University of Oxford, Oxford, UK.
  • 5 Institut de Chimie des Substances Naturelles, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France.
  • 6 Center for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, the Netherlands.
  • 7 The Rosalind Franklin Institute, Didcot, UK.
  • 8 Department of Biochemistry, University of Zurich, Zurich, Switzerland.
  • 9 Center for Translational Immunology, University Medical Centre Utrecht, Utrecht, the Netherlands.
  • 10 Department of Pediatric Infectious Diseases and Immunology, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, the Netherlands.
  • 11 Respiratory Syncytial Virus Network (ResViNET) Foundation, Zeist, the Netherlands.
  • 12 Department of Chemistry, University of Oxford, Oxford, UK.
  • 13 M3P unit, Institut Pasteur, Université Paris Cité, Paris, France.
  • 14 UMR 1173 (2I), INSERM, Université de Versailles St. Quentin, Université Paris-Saclay, Paris, France.
  • 15 Hôpital Ambroise Paré, Assistance Publique des Hôpitaux de Paris, Paris, France.
  • 16 Oncode Institute, Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, Utrecht, the Netherlands. [email protected].
  • 17 Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Technische Universiteit Delft, Delft, the Netherlands. [email protected].
  • # Contributed equally.
PMID: 41606345 DOI: 10.1038/s41586-025-10071-5
Abstract

During Infection, many RNA viruses, including respiratory syncytial virus (RSV), form specialized biomolecular condensates, viral factories (VFs), where viral transcription and replication occur1,2. Paradoxically, high protein concentrations are typically required for condensate nucleation3, yet attaining sufficient protein levels in Infection is thought to require VFs for viral transcription and replication. Here, to uncover how viruses solve this paradox to establish VFs, we visualized early Infection of RSV in real time with single genomic viral ribonucleoprotein (vRNP) resolution. Our results reveal that VFs are nucleated from infecting vRNPs rather than de novo in the cytoplasm. VF nucleation further requires in-virion pre-assembly of viral protein-protein interaction networks on vRNPs to form 'pre-replication centres' (PRCs). PRCs are potent condensate nucleation seeds due to their efficient recruitment and retention of Viral Proteins. The high affinity of PRCs also results in increased association of the viral polymerase and its co-factors, allowing efficient viral transcription even in the absence of VFs. Together, these activities create a feed-forward loop that drives rapid VF formation. PRC assembly depends on in-virion viral protein levels and is highly heterogeneous among virions, explaining cell-to-cell heterogeneity in Infection progression, and identifying heterogeneous virions as an important origin of Infection heterogeneity. Together, our results show that in-virion pre-assembly of PRCs kick-starts viral condensate nucleation upon host-cell entry and explains cell-to-cell heterogeneity in RSV Infection.

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