Terminal cytokinesis events uncovered after an RNAi screen

Curr Biol. 2004 Sep 21;14(18):1685-93. doi: 10.1016/j.cub.2004.08.063.

Abstract

Much of our understanding of animal cell cytokinesis centers on the regulation of the equatorial acto-myosin contractile ring that drives the rapid ingression of a deep cleavage furrow. However, the central part of the mitotic spindle collapses to a dense structure that impedes the furrow and keeps the daughter cells connected via an intercellular bridge. Factors involved in the formation, maintenance, and resolution of this bridge are largely unknown. Using a library of 7,216 double-stranded RNAs (dsRNAs) representing the conserved genes of Drosophila, we performed an RNA interference (RNAi) screen for cytokinesis genes in Schneider's S2 cells. We identified both familiar and novel genes whose inactivation induced a multi-nucleate phenotype. Using live video microscopy, we show that three genes: anillin, citron-kinase (CG10522), and soluble N-ethylmaleimide sensitive factor (NSF) attachment protein (alpha-SNAP), are essential for the terminal (post-furrowing) events of cytokinesis. anillin RNAi caused gradual disruption of the intercellular bridge after furrowing; citron-kinase RNAi destabilized the bridge at a later stage; alpha-SNAP RNAi caused sister cells to fuse many hours later and by a different mechanism. We have shown that the stability of the intercellular bridge is essential for successful cytokinesis and have defined genes contributing to this stability.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Actins / metabolism
  • Animals
  • Cells, Cultured
  • Contractile Proteins / genetics
  • Contractile Proteins / physiology
  • Cytokinesis / physiology*
  • Drosophila
  • Gene Library
  • Intracellular Signaling Peptides and Proteins
  • Microscopy, Video
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / physiology
  • RNA Interference
  • RNA, Double-Stranded / genetics
  • Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins
  • Spindle Apparatus / physiology*
  • Vesicular Transport Proteins / genetics
  • Vesicular Transport Proteins / physiology

Substances

  • Actins
  • Contractile Proteins
  • Intracellular Signaling Peptides and Proteins
  • RNA, Double-Stranded
  • Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins
  • Vesicular Transport Proteins
  • anillin
  • citron-kinase
  • Protein-Serine-Threonine Kinases