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.