Mitogen-activated protein kinase 4 is involved in the regulation of mitotic and cytokinetic microtubule transitions in Arabidopsis thaliana

New Phytol. 2011 Mar;189(4):1069-83. doi: 10.1111/j.1469-8137.2010.03565.x. Epub 2010 Dec 14.


• A mitogen-activated protein kinase kinase kinase (MAPKKK) double mutant, Arabidopsis homologue of nucleus and phragmoplast associated kinase (anp) anp2anp3, and the mitogen-activated protein kinase (MAPK) 4 mutant mpk4 of Arabidopsis thaliana show prominent cytokinetic defects. This prompted the analysis of mitotic and cytokinetic progression as a function of MAPK signalling. Mutants were compared with wild types untreated or treated with the specific MAPKK inhibitor PD98059. • This study included phenotype analysis, expression analysis of the MPK4 promoter, immunofluorescent localization of MPK4, tubulin and MAP65-1, and time-lapse microscopic visualization of the mitotic microtubule (MT) transitions in control, mutant and inhibitor-treated cells. • Mutant and inhibitor-treated cells showed defects in mitosis and cytokinesis, including aberrant spindle and phragmoplast formation and drastically delayed or abortive mitosis and cytokinesis. As a result, bi- and multinucleate cells were formed, ultimately disturbing the vegetative tissue patterning. MPK4 was localized to all stages of the expanding phragmoplast, in a pattern similar to that of its putative substrate MAP65-1. • In this study, MPK4 is shown to be involved in the regulation of mitosis/cytokinesis through modulation of the cell division plane and cytokinetic progression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / cytology*
  • Arabidopsis / drug effects
  • Arabidopsis / enzymology*
  • Arabidopsis Proteins / antagonists & inhibitors
  • Arabidopsis Proteins / metabolism*
  • Cell Nucleus / drug effects
  • Cell Nucleus / metabolism
  • Cell Survival / drug effects
  • Cytokinesis* / drug effects
  • Flavonoids / pharmacology
  • Fluorescent Antibody Technique
  • Imaging, Three-Dimensional
  • Meristem / cytology
  • Meristem / drug effects
  • Meristem / enzymology
  • Microscopy, Fluorescence
  • Microtubule-Associated Proteins / metabolism
  • Microtubules / drug effects
  • Microtubules / metabolism*
  • Mitogen-Activated Protein Kinases / antagonists & inhibitors
  • Mitogen-Activated Protein Kinases / metabolism*
  • Mitosis* / drug effects
  • Mutation / genetics
  • Phenotype
  • Protein Kinase Inhibitors / pharmacology
  • Spindle Apparatus / drug effects
  • Spindle Apparatus / metabolism


  • Arabidopsis Proteins
  • Flavonoids
  • MAP65-1 protein, Arabidopsis
  • Microtubule-Associated Proteins
  • Protein Kinase Inhibitors
  • AtMPK4 protein, Arabidopsis
  • Mitogen-Activated Protein Kinases
  • 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one