Kinesin-14 and kinesin-5 antagonistically regulate microtubule nucleation by γ-TuRC in yeast and human cells

• Published in: Nature communications 2014-10, Vol.5 (1), p.5339, Article 5339
• Main Authors: Olmsted, Zachary T., Colliver, Andrew G., Riehlman, Timothy D., Paluh, Janet L.
• Format: Article
• Language: English
• Subjects: 13/1; 631/67/1347; 631/80/128/1653; 631/80/641/1655; 631/80/86; 82/80; 96/106; 96/109; 96/44; 96/63; Breast Neoplasms - metabolism; Breast Neoplasms - pathology; Cell Line, Tumor; Chromosome Segregation - drug effects; Female; Humanities and Social Sciences; Humans; Kinesin - chemistry; Kinesin - metabolism; MCF-7 Cells; Microbial Viability - drug effects; Microtubule-Organizing Center - drug effects; Microtubule-Organizing Center - metabolism; Microtubules - drug effects; Microtubules - metabolism; multidisciplinary; Mutation - genetics; Peptides - pharmacology; Protein Binding - drug effects; Protein Structure, Tertiary; Schizosaccharomyces - drug effects; Schizosaccharomyces - metabolism; Schizosaccharomyces pombe Proteins - metabolism; Science; Science (multidisciplinary); Spindle Apparatus - drug effects; Spindle Apparatus - metabolism; Tubulin - metabolism
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms6339

Bipolar spindle assembly is a critical control point for initiation of mitosis through nucleation and organization of spindle microtubules and is regulated by kinesin-like proteins. In fission yeast, the kinesin-14 Pkl1 binds the γ-tubulin ring complex (γ-TuRC) microtubule-organizing centre at spindle poles and can alter its structure and function. Here we show that kinesin-14 blocks microtubule nucleation in yeast and reveal that this inhibition is countered by the kinesin-5 protein, Cut7. Furthermore, we demonstrate that Cut7 binding to γ-TuRC and the Cut7 BimC domain are both required for inhibition of Pkl1. We also demonstrate that a yeast kinesin-14 peptide blocks microtubule nucleation in two human breast cancer cell lines, suggesting that this mechanism is evolutionarily conserved. In conclusion, using genetic, biochemical and cell biology approaches we uncover antagonistic control of microtubule nucleation at γ-TuRC by two kinesin-like proteins, which may represent an attractive anti-mitotic target for cancer therapies. Mitotic spindle assembly requires strict control of microtubule nucleation by γ-tubulin ring complexes. Olmsted et al . report that the kinesin-like proteins Pkl1 and Cut7 antagonistically regulate nucleation in fission yeast, and show that a Pkl1 peptide blocks spindle assembly in human cancer cells.