Nuclear pores protect genome integrity by assembling a premitotic and Mad1-dependent anaphase inhibitor

Cell. 2014 Feb 27;156(5):1017-31. doi: 10.1016/j.cell.2014.01.010.

Abstract

The spindle assembly checkpoint (SAC) delays anaphase until all chromosomes are bioriented on the mitotic spindle. Under current models, unattached kinetochores transduce the SAC by catalyzing the intramitotic production of a diffusible inhibitor of APC/C(Cdc20) (the anaphase-promoting complex/cyclosome and its coactivator Cdc20, a large ubiquitin ligase). Here we show that nuclear pore complexes (NPCs) in interphase cells also function as scaffolds for anaphase-inhibitory signaling. This role is mediated by Mad1-Mad2 complexes tethered to the nuclear basket, which activate soluble Mad2 as a binding partner and inhibitor of Cdc20 in the cytoplasm. Displacing Mad1-Mad2 from nuclear pores accelerated anaphase onset, prevented effective correction of merotelic errors, and increased the threshold of kinetochore-dependent signaling needed to halt mitosis in response to spindle poisons. A heterologous Mad1-NPC tether restored Cdc20 inhibitor production and normal M phase control. We conclude that nuclear pores and kinetochores both emit "wait anaphase" signals that preserve genome integrity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Active Transport, Cell Nucleus
  • Anaphase*
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Dimerization
  • HCT116 Cells
  • HeLa Cells
  • Humans
  • Interphase
  • Kinetochores / metabolism
  • M Phase Cell Cycle Checkpoints*
  • Mad2 Proteins / metabolism*
  • Mitosis
  • Nuclear Pore / metabolism*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*

Substances

  • Cell Cycle Proteins
  • MAD1L1 protein, human
  • MAD2L1 protein, human
  • Mad2 Proteins
  • Nuclear Proteins