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Updated: Sep 29, 2025
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Identification of Nucleolar Factors During HIV-1 Replication Through Rev Immunoprecipitation and Mass Spectrometry
Published on: June 26, 2019
8.2K
Ribosomal protein L5 facilitates rDNA-bundled condensate and nucleolar assembly.
Haruka Matsumori1, Kenji Watanabe2, Hiroaki Tachiwana2
1Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan.
Life Science Alliance
|March 24, 2022
Summary
The nucleolus disassembles when RPL5 protein is depleted, disrupting ribosome production and DNA organization. This finding sheds light on nucleolar function and ribosomopathy causes.
Area of Science:
- Cell Biology
- Biophysics
- Molecular Genetics
Background:
- The nucleolus is central to ribosome biogenesis, assembling ribosomes via liquid-liquid phase separation.
- The mechanism and importance of bundled ribosomal DNA (rDNA) arrays within the nucleolus remain unclear.
Purpose of the Study:
- To investigate the role of ribosomal proteins in nucleolar integrity and function.
- To elucidate the mechanism of ribosomal DNA (rDNA) array organization within the nucleolus.
Main Methods:
- High-content screening and image profiling using the wndchrm machine learning algorithm.
- Single-molecule tracking and coarse-grained molecular dynamics modeling.
- Analysis of patient-derived cells with Diamond-Blackfan anemia.
Main Results:
- Depletion of the 60S ribosomal protein RPL5 caused nucleolar disintegration and enlarged, un-separated sub-nucleolar compartments.
- RPL5 depletion led to less constrained component mobility, unbundled rDNA arrays, and repressed ribosomal RNA transcription and processing.
- Disordered nucleoli were observed in Diamond-Blackfan anemia patient cells with an RPL5 deletion.
Conclusions:
- RPL5 is crucial for maintaining nucleolar structure, including rDNA array bundling and proper biophysical properties.
- RPL5's role in nucleolar organization is linked to the etiology of ribosomopathies like Diamond-Blackfan anemia.
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