Arabidopsis Fused kinase and the Kinesin-12 subfamily constitute a signalling module required for phragmoplast expansion

Plant J. 2012 Oct;72(2):308-19. doi: 10.1111/j.1365-313X.2012.05077.x. Epub 2012 Jul 24.


The conserved Fused kinase plays vital but divergent roles in many organisms from Hedgehog signalling in Drosophila to polarization and chemotaxis in Dictyostelium. Previously we have shown that Arabidopsis Fused kinase termed TWO-IN-ONE (TIO) is essential for cytokinesis in both sporophytic and gametophytic cell types. Here using in vivo imaging of GFP-tagged microtubules in dividing microspores we show that TIO is required for expansion of the phragmoplast. We identify the phragmoplast-associated kinesins, PAKRP1/Kinesin-12A and PAKRP1L/Kinesin-12B, as TIO-interacting proteins and determine TIO-Kinesin-12 interaction domains and their requirement in male gametophytic cytokinesis. Our results support the role of TIO as a functional protein kinase that interacts with Kinesin-12 subfamily members mainly through the C-terminal ARM repeat domain, but with a contribution from the N-terminal kinase domain. The interaction of TIO with Kinesin proteins and the functional requirement of their interaction domains support the operation of a Fused kinase signalling module in phragmoplast expansion that depends upon conserved structural features in diverse Fused kinases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • Arabidopsis / cytology
  • Arabidopsis / enzymology*
  • Arabidopsis / genetics
  • Arabidopsis / physiology
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Cytokinesis*
  • Green Fluorescent Proteins
  • Kinesins / genetics
  • Kinesins / metabolism
  • Microtubules / genetics
  • Microtubules / metabolism*
  • Models, Biological
  • Mutation
  • Phenotype
  • Pollen / cytology
  • Pollen / enzymology
  • Pollen / genetics
  • Pollen / physiology
  • Protein Kinases / genetics
  • Protein Kinases / metabolism
  • Protein Structure, Tertiary
  • Recombinant Fusion Proteins
  • Signal Transduction
  • Two-Hybrid System Techniques


  • Arabidopsis Proteins
  • Recombinant Fusion Proteins
  • Green Fluorescent Proteins
  • Protein Kinases
  • PAKRP1 protein, Arabidopsis
  • Pakrp1l protein, Arabidopsis
  • Kinesins