The kinesin-like protein TOP promotes aurora localisation and induces mitochondrial, chloroplast and nuclear division

Yamato Yoshida, Takayuki Fujiwara, Yuuta Imoto, Masaki Yoshida, Mio Ohnuma, Shunsuke Hirooka, Osami Misumi, Haruko Kuroiwa, Shoichi Kato, Sachihiro Matsunaga, Tsuneyoshi Kuroiwa

Research output: Contribution to journalArticlepeer-review


The cell cycle usually refers to the mitotic cycle, but the cell-division cycle in the plant kingdom consists of not only nuclear but also mitochondrial and chloroplast division cycle. However, an integrated control system that initiates division of the three organelles has not been found. We report that a novel C-terminal kinesin-like protein, three-organelle division-inducing protein (TOP), controls nuclear, mitochondrial and chloroplast divisions in the red alga Cyanidioschyzon merolae. A proteomics study revealed that TOP is a member of a complex of mitochondrial-dividing (MD) and plastid-dividing (PD) machineries (MD/PD machinery complex) just prior to constriction. After TOP localizes at the MD/PD machinery complex, mitochondrial and chloroplast divisions occur and the components of the MD/PD machinery complexes are phosphorylated. Furthermore, we found that TOP downregulation impaired both mitochondrial and chloroplast divisions. MD/PD machinery complexes were formed normally at each division site but they were neither phosphorylated nor constricted in these cells. Immunofluorescence signals of Aurora kinase (AUR) were localized around the MD machinery before constriction, whereas AUR was dispersed in the cytosol by TOP downregulation, suggesting that AUR is required for the constriction. Taken together our results suggest that TOP induces phosphorylation of MD/PD machinery components to accomplish mitochondrial and chloroplast divisions prior to nuclear division, by relocalization of AUR. In addition, given the presence of TOP homologs throughout the eukaryotes, and the involvement of TOP in mitochondrial and chloroplast division may illuminate the original function of C-terminal kinesin-like proteins.

Original languageEnglish (US)
Pages (from-to)2392-2400
Number of pages9
JournalJournal of cell science
Issue number11
StatePublished - Jun 2013
Externally publishedYes


  • Cell-division cycle
  • Cyanidioschyzon merolae
  • Kinesin
  • Mitochondrial division
  • Plastid division

ASJC Scopus subject areas

  • Cell Biology


Dive into the research topics of 'The kinesin-like protein TOP promotes aurora localisation and induces mitochondrial, chloroplast and nuclear division'. Together they form a unique fingerprint.

Cite this