Directionality of individual kinesin-5 Cin8 motors is modulated by loop 8, ionic strength and microtubule geometry

Adina Gerson-Gurwitz, Christina Thiede, Natalia Movshovich, Vladimir Fridman, Maria Podolskaya, Tsafi Danieli, Stefan Lakämper, Dieter R. Klopfenstein, Christoph F. Schmidt, Larisa Gheber

Research output: Contribution to journalArticlepeer-review

80 Scopus citations

Abstract

Kinesin-5 motors fulfil essential roles in mitotic spindle morphogenesis and dynamics as slow, processive microtubule (MT) plus-end directed motors. The Saccharomyces cerevisiae kinesin-5 Cin8 was found, surprisingly, to switch directionality. Here, we have examined directionality using single-molecule fluorescence motility assays and live-cell microscopy. On spindles, Cin8 motors mostly moved slowly (∼25 nm/s) towards the midzone, but occasionally also faster (∼55 nm/s) towards the spindle poles. In vitro, individual Cin8 motors could be switched by ionic conditions from rapid (380 nm/s) and processive minus-end to slow plus-end motion on single MTs. At high ionic strength, Cin8 motors rapidly alternated directionalities between antiparallel MTs, while driving steady plus-end relative sliding. Between parallel MTs, plus-end motion was only occasionally observed. Deletion of the uniquely large insert in loop 8 of Cin8 induced bias towards minus-end motility and affected the ionic strength-dependent directional switching of Cin8 in vitro. The deletion mutant cells exhibited reduced midzone-directed motility and efficiency to support spindle elongation, indicating the importance of directionality control for the anaphase function of Cin8.

Original languageEnglish
Pages (from-to)4942-4954
Number of pages13
JournalEMBO Journal
Volume30
Issue number24
DOIs
StatePublished - 14 Dec 2011

Keywords

  • Cin8
  • kinesin directionality
  • kinesin-5
  • microtubules
  • mitosis

ASJC Scopus subject areas

  • General Neuroscience
  • Molecular Biology
  • General Biochemistry, Genetics and Molecular Biology
  • General Immunology and Microbiology

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