Beclin-1 is required for chromosome congression and proper outer kinetochore assembly

EMBO Rep. 2013 Apr;14(4):364-72. doi: 10.1038/embor.2013.23. Epub 2013 Mar 12.

Abstract

The functions of Beclin-1 in macroautophagy, tumorigenesis and cytokinesis are thought to be mediated by its association with the PI3K-III complex. Here, we describe a new role for Beclin-1 in mitotic chromosome congression that is independent of the PI3K-III complex and its role in autophagy. Beclin-1 depletion in HeLa cells leads to a significant reduction of the outer kinetochore proteins CENP-E, CENP-F and ZW10, and, consequently, the cells present severe problems in chromosome congression. Beclin-1 associates with kinetochore microtubules and forms discrete foci near the kinetochores of attached chromosomes. We show that Beclin-1 interacts directly with Zwint-1-a component of the KMN (KNL-1/Mis12/Ndc80) complex-which is essential for kinetochore-microtubule interactions. This suggests that Beclin-1 acts downstream of the KMN complex to influence the recruitment of outer kinetochore proteins and promotes accurate kinetochore anchoring to the spindle during mitosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis Regulatory Proteins / physiology*
  • Beclin-1
  • Chromosome Segregation
  • Chromosomes, Human / metabolism*
  • Gene Knockdown Techniques
  • HeLa Cells
  • Humans
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Kinetochores / metabolism*
  • Membrane Proteins / physiology*
  • Microscopy, Fluorescence
  • Mitosis
  • Nuclear Proteins / metabolism
  • Protein Binding
  • RNA, Small Interfering / genetics
  • Time-Lapse Imaging

Substances

  • Apoptosis Regulatory Proteins
  • BECN1 protein, human
  • Beclin-1
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • Nuclear Proteins
  • RNA, Small Interfering
  • ZWINT protein, human