Aurora A regulates the material property of spindle poles to orchestrate nuclear organization at mitotic exit

  • EMBO J. 2025 Sep 12. doi: 10.1038/s44318-025-00564-4.
Ashwathi Rajeevan  #  1 Vignesh Olakkal  #  1 Madhumitha Balakrishnan  #  1 Dwaipayan Chakrabarty  #  1 François Charon  2 Daan Noordermeer  2 Sachin Kotak  3
Affiliations
  • 1. Department of Microbiology and Cell Biology (MCB), Indian Institute of Science (IISc), 560012, Bangalore, India.
  • 2. Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France.
  • 3. Department of Microbiology and Cell Biology (MCB), Indian Institute of Science (IISc), 560012, Bangalore, India. [email protected].
  • # Contributed equally.
Abstract

Animal cells dismantle their nuclear envelope (NE) at the beginning and reconstruct it at the end of Mitosis. This process is closely coordinated with spindle pole organization: poles enlarge at mitotic onset and reduce in size as Mitosis concludes. The significance of this coordination remains unknown. Here, we demonstrate that Aurora A maintains a pole-localized protein NuMA in a dynamic state during anaphase. Without Aurora A activity, NuMA shifts from a dynamic to a solid state and abnormally accumulates at the poles, causing the segregated chromosome sets to bend around the NuMA-enriched poles. NuMA localization at the poles relies on interactions with dynein/dynactin, its coiled-coil domain, and an intrinsically disordered region (IDR). Mutagenesis experiments revealed that cation-π interactions within IDR are key for NuMA pole localization, while glutamine residues trigger the solid-state transition of NuMA upon Aurora A inhibition. We propose that maintaining the proper material properties of the spindle poles is a key step in choreographing the accurate organization of the nucleus and genome post-mitosis.

Keywords
Aurora A; Material Property; NuMA; Nuclear Shape; Spindle Poles.
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