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A mechanism that integrates microtubule motors of opposite polarity at the kinetochore corona.

Verena CmentowskiGiuseppe CiossaniEnnio A d'AmicoSabine WohlgemuthMikito OwaBrian D DynlachtAndrea Musacchio
Published in: bioRxiv : the preprint server for biology (2023)
Chromosome biorientation on the mitotic spindle is prerequisite to errorless genome inheritance. CENP-E (kinesin 7) and Dynein-Dynactin (DD), microtubule motors with opposite polarity, promote biorientation from the kinetochore corona, a polymeric structure whose assembly requires MPS1 kinase. The corona's building block consists of ROD, Zwilch, ZW10, and the DD adaptor Spindly (RZZS). How CENP-E and DD are scaffolded and mutually coordinated in the corona remains unclear. Here, we report near-complete depletion of RZZS and DD from kinetochores after depletion of CENP-E and the outer kinetochore protein KNL1. With inhibited MPS1, CENP-E, which we show binds directly to RZZS, is required to retain kinetochore RZZS. An RZZS phosphomimetic mutant bypasses this requirement. With active MPS1, CENP-E is dispensable for corona expansion, but strictly required for physiological kinetochore accumulation of DD. Thus, we identify the corona as an integrated scaffold where CENP-E kinesin controls DD kinetochore loading for coordinated bidirectional transport of chromosome cargo.
Keyphrases
  • mitochondrial dna
  • copy number
  • cell cycle
  • binding protein
  • protein protein
  • cell proliferation
  • gene expression
  • small molecule