Bicaudal D2, dynein, and kinesin-1 associate with nuclear pore complexes and regulate centrosome and nuclear positioning during mitotic entry

PLoS Biol. 2010 Apr 6;8(4):e1000350. doi: 10.1371/journal.pbio.1000350.

Abstract

BICD2 is one of the two mammalian homologues of the Drosophila Bicaudal D, an evolutionarily conserved adaptor between microtubule motors and their cargo that was previously shown to link vesicles and mRNP complexes to the dynein motor. Here, we identified a G2-specific role for BICD2 in the relative positioning of the nucleus and centrosomes in dividing cells. By combining mass spectrometry, biochemical and cell biological approaches, we show that the nuclear pore complex (NPC) component RanBP2 directly binds to BICD2 and recruits it to NPCs specifically in G2 phase of the cell cycle. BICD2, in turn, recruits dynein-dynactin to NPCs and as such is needed to keep centrosomes closely tethered to the nucleus prior to mitotic entry. When dynein function is suppressed by RNA interference-mediated depletion or antibody microinjection, centrosomes and nuclei are actively pushed apart in late G2 and we show that this is due to the action of kinesin-1. Surprisingly, depletion of BICD2 inhibits both dynein and kinesin-1-dependent movements of the nucleus and cytoplasmic NPCs, demonstrating that BICD2 is needed not only for the dynein function at the nuclear pores but also for the antagonistic activity of kinesin-1. Our study demonstrates that the nucleus is subject to opposing activities of dynein and kinesin-1 motors and that BICD2 contributes to nuclear and centrosomal positioning prior to mitotic entry through regulation of both dynein and kinesin-1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Line
  • Cell Nucleus / metabolism*
  • Cell Nucleus / ultrastructure
  • Centrosome / metabolism*
  • Dynactin Complex
  • Dyneins / metabolism*
  • Humans
  • Kinesin / genetics
  • Kinesin / metabolism*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice
  • Microtubule-Associated Proteins / metabolism
  • Mitosis / physiology*
  • Molecular Chaperones / genetics
  • Molecular Chaperones / metabolism
  • Nuclear Pore / metabolism*
  • Nuclear Pore Complex Proteins / genetics
  • Nuclear Pore Complex Proteins / metabolism
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Spindle Apparatus / metabolism
  • Two-Hybrid System Techniques

Substances

  • Bicd2 protein, mouse
  • Carrier Proteins
  • Dynactin Complex
  • KIF11 protein, human
  • Membrane Proteins
  • Microtubule-Associated Proteins
  • Molecular Chaperones
  • Nuclear Pore Complex Proteins
  • RNA, Small Interfering
  • Recombinant Fusion Proteins
  • ran-binding protein 2
  • Dyneins
  • Kinesin