Nuclear mitotic apparatus (numa) interacts with and regulates astrin at the mitotic spindle

Xiaogang Chu, Xuanyu Chen, Qingwen Wan, Zhen Zheng, Quansheng Du

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

The large nuclear mitotic apparatus (NuMA) protein is an essential player in mitotic spindle assembly and maintenance. We report here the identification of Astrin, a spindle- and kinetochore-associated protein, as a novel interactor of NuMA. We show that the C-terminal tail of NuMA can directly bind to the C terminus of Astrin and that this interaction helps to recruit Astrin to microtubules. Knockdown of NuMA by RNA interference dramatically impaired Astrin recruitment to the mitotic spindle. Overexpression of the N terminus of mammalian homologue of Drosophila Pins (LGN), which blocks the microtubule binding of NuMA and competes with Astrin for NuMA binding, also led to similar results. Furthermore, we found that cytoplasmic dynein is required for the spindle pole accumulation of Astrin, and dynein-mediated transport is important for balanced distribution of Astrin between spindle poles and kinetochores. On the other hand, if Astrin levels are reduced, then NuMA could not efficiently concentrate at the spindle poles. Our findings reveal a direct physical link between two important regulators of mitotic progression and demonstrate the critical role of the NuMA-Astrin interaction for accurate cell division.

Original languageEnglish (US)
Pages (from-to)20055-20067
Number of pages13
JournalJournal of Biological Chemistry
Volume291
Issue number38
DOIs
StatePublished - Sep 16 2016

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ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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