In eukaryotic cell nuclei, specific sets of proteins gather in nuclear bodies and facilitate distinct genomic processes. The nucleolus, a nuclear body, functions as a factory for ribosome biogenesis by accumulating constitutive proteins, such as RNA polymerase I and nucleophosmin 1 (NPM1). Although in vitro assays have suggested the importance of liquid-liquid phase separation (LLPS) of constitutive proteins in nucleolar formation, how the nucleolus is structurally maintained with intranuclear architecture remains unknown. This study revealed that the nucleolus is encapsulated by single-stranded (ss) DNA-based molecular complex inside the cell nucleus. Super-resolution lattice-structured illumination microscopy (lattice-SIM) showed high abundance of ssDNA beyond the "outer shell" of the nucleolus. Nucleolar disruption and the release of NPM1 were caused by in situ digestion of ssDNA, suggesting that ssDNA has a structural role in nucleolar encapsulation. Furthermore, we identified that ssDNA forms molecular complex with histone H1 for nucleolar encapsulation. Thus, this study illustrates how ssDNA-based molecular complex uphold the structural integrity of nuclear bodies to coordinate genomic processes such as gene transcription and replication.
Super-resolution imaging reveals nucleolar encapsulation by single-stranded DNA
Call for papers: Cell Biology of Mitochondria
We are welcoming submissions for our upcoming special issue: Cell Biology of Mitochondria. This issue will be coordinated by two Guest Editors: Ana J. Garcia-Saez (University of Cologne, Germany) and Heidi McBride (McGill University, Canada). Submission deadline: 1 October 2024.
Focal adhesion kinase signalling – tumour vulnerabilities and clinical opportunities
In this Review, David Schlaepfer and colleagues summarise 30 years of focal adhesion kinase (FAK) research with a view of the ongoing clinical testing of small-molecule FAK inhibitors. The authors touch on how FAK plays an important signal integration role and ultimately functions to guide cellular behaviour. Additionally, the authors discuss how FAK inhibition might present a powerful tool to influence the physiological response to other therapeutic approaches.
JCS-FocalPlane Training Grants
Early-career researchers - working in an area covered by JCS - who would like to attend a microscopy training course, please apply. Deadline dates for 2024 applications: 7 September (decision by week commencing 8 October 2024); 22 November (decision by week commencing 16 December).
Biologists @ 100 - join us in Liverpool in March 2025
We are excited to invite you to a unique scientific conference, celebrating the 100-year anniversary of The Company of Biologists, and bringing together our different communities. The conference will incorporate the Spring Meetings of the BSCB and the BSDB, the JEB Symposium Sensory Perception in a Changing World and a DMM programme on antimicrobial resistance. Find out more and register your interest to join us in March 2025 in Liverpool, UK.
Interview with Journal of Cell Science Editor Rob Parton
Read our interview with Rob Parton, a Cell Scientist to Watch, about his career journey leading him from the UK to the University of Queensland in Brisbane, Australia, the evolution of the membrane trafficking field and his advice for running a highly collaborative lab. As a Journal of Cell Science Editor, Rob brings to the journal his expertise in multiscale analysis of membrane function, membrane microdomains, lipid droplets and advanced microscopy techniques in cell biology.
Social media
