FIP3-endosome-dependent formation of the secondary ingression mediates ESCRT-III recruitment during cytokinesis

Nat Cell Biol. 2012 Oct;14(10):1068-78. doi: 10.1038/ncb2577. Epub 2012 Sep 23.

Abstract

The final cytokinesis event involves severing of the connecting intercellular bridge (ICB) between daughter cells. FIP3-positive recycling endosomes (FIP3 endosomes) and ESCRT complexes have been implicated in mediating the final stages of cytokinesis. Here we analyse the spatiotemporal dynamics of the actin cytoskeleton, FIP3-endosome fusion and ESCRT-III localization during cytokinesis to show that the ICB narrows by a FIP3-endosome-mediated secondary ingression, whereas the ESCRT-III complex is needed only for the last scission step of cytokinesis. We characterize the role of FIP3 endosomes during cytokinesis to demonstrate that FIP3 endosomes deliver SCAMP2/3 and p50RhoGAP to the ICB during late telophase, proteins required for the formation of the secondary ingression. We also show that the FIP3-endosome-induced secondary ingression is required for the recruitment of the ESCRT-III complex to the abscission site. Finally, we characterize a FIP3-endosome-dependent regulation of the ICB cortical actin network through the delivery of p50RhoGAP. These results provide a framework for the coordinated efforts of actin, FIP3 endosomes and the ESCRTs to regulate cytokinesis and abscission.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Actins / physiology
  • Carrier Proteins / physiology
  • Cytokinesis*
  • Cytoskeleton / physiology
  • Endosomal Sorting Complexes Required for Transport / physiology*
  • Endosomes / physiology*
  • GTPase-Activating Proteins / physiology
  • HeLa Cells
  • Humans
  • I-kappa B Kinase / physiology*
  • Membrane Proteins / physiology
  • Telophase / physiology

Substances

  • Actins
  • Carrier Proteins
  • Endosomal Sorting Complexes Required for Transport
  • GTPase-Activating Proteins
  • IKBKG protein, human
  • Membrane Proteins
  • SCAMP2 protein, human
  • SCAMP3 protein, human
  • rho GTPase-activating protein
  • I-kappa B Kinase