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Publications

Journal Article Research Support, Non-U.S. Gov't Epublish 1 citation

PubMed: 38263258 DOI: 10.1038/s42003-023-05750-w

The nucleolar shell provides anchoring sites for DNA untwisting.

Commun Biol 7(1):83

Authors: Jumpei Fukute, Koichiro Maki, Taiji Adachi

Affiliations

  • Laboratory of Cellular and Molecular Biomechanics, Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Sakyo, Kyoto, Japan. Laboratory of Biomechanics, Institute for Life and Medical Sciences, Kyoto University, Sakyo, Kyoto, Japan.
  • Laboratory of Cellular and Molecular Biomechanics, Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Sakyo, Kyoto, Japan.
  • Laboratory of Biomechanics, Institute for Life and Medical Sciences, Kyoto University, Sakyo, Kyoto, Japan.
  • Department of Micro Engineering, Graduate School of Engineering, Kyoto University, Sakyo, Kyoto, Japan.
  • Department of Medicine and Medical Science, Graduate School of Medicine, Kyoto University, Sakyo, Kyoto, Japan.
  • Laboratory of Cellular and Molecular Biomechanics, Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Sakyo, Kyoto, Japan.
  • Laboratory of Biomechanics, Institute for Life and Medical Sciences, Kyoto University, Sakyo, Kyoto, Japan.
  • Department of Micro Engineering, Graduate School of Engineering, Kyoto University, Sakyo, Kyoto, Japan.
  • Department of Medicine and Medical Science, Graduate School of Medicine, Kyoto University, Sakyo, Kyoto, Japan.

Abstract

DNA underwinding (untwisting) is a crucial step in transcriptional activation. DNA underwinding occurs between the site where torque is generated by RNA polymerase (RNAP) and the site where the axial rotation of DNA is constrained. However, what constrains DNA axial rotation in the nucleus is yet unknown. Here, we show that the anchorage to the nuclear protein condensates constrains DNA axial rotation for DNA underwinding in the nucleolus. In situ super-resolution imaging of underwound DNA reveal that underwound DNA accumulates in the nucleolus, a nuclear condensate with a core-shell structure. Specifically, underwound DNA is distributed in the nucleolar core owing to RNA polymerase I (RNAPI) activities. Furthermore, underwound DNA in the core decreases when nucleolar shell components are prevented from binding to their recognition structure, G-quadruplex (G4). Taken together, these results suggest that the nucleolar shell provides anchoring sites that constrain DNA axial rotation for RNAPI-driven DNA underwinding in the core. Our findings will contribute to understanding how nuclear protein condensates make up constraints for the site-specific regulation of DNA underwinding and transcription.

MeSH

Biological Science Disciplines, Dna, Rna Polymerase I