Identification of Phosphoinositide-Binding Protein PATELLIN2 as a Substrate of Arabidopsis MPK4 MAP Kinase during Septum Formation in Cytokinesis

Plant Cell Physiol. 2016 Aug;57(8):1744-55. doi: 10.1093/pcp/pcw098. Epub 2016 May 19.


The phosphorylation of proteins by protein kinases controls many cellular and physiological processes, which include intracellular signal transduction. However, the underlying molecular mechanisms of such controls and numerous substrates of protein kinases remain to be characterized. The mitogen-activated protein kinase (MAPK) cascade is of particular importance in a variety of extracellular and intracellular signaling processes. In plant cells, the progression of cytokinesis is an excellent example of an intracellular phenomenon that requires the MAPK cascade. However, the way in which MAPKs control downstream processes during cytokinesis in plant cells remains to be fully determined. We show here that comparisons, by two-dimensional difference gel electrophoresis, of phosphorylated proteins from wild-type Arabidopsis thaliana and mutant plants defective in a MAPK cascade allow identification of substrates of a specific MAPK. Using this method, we identified the PATELLIN2 (PATL2) protein, which has a SEC14 domain, as a substrate of MPK4 MAP kinase. PATL2 was concentrated at the cell division plane, as is MPK4, and had binding affinity for phosphoinositides. This binding affinity was altered after phosphorylation of PATL2 by MPK4, suggesting a role for the MAPK cascade in the formation of cell plates via regeneration of membranes during cytokinesis.

Keywords: Cytokinesis; MAP kinase; Membrane protein PATL2; Phosphoinositide-binding protein; Phosphoproteomics; SEC14–GOLD domain.

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / cytology
  • Arabidopsis / genetics*
  • Arabidopsis / physiology
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Cytokinesis
  • Genes, Reporter
  • MAP Kinase Signaling System*
  • Mitogen-Activated Protein Kinases / genetics*
  • Mitogen-Activated Protein Kinases / metabolism
  • Phosphatidylinositols / metabolism*
  • Phosphorylation
  • Plant Roots / cytology
  • Plant Roots / genetics
  • Plant Roots / physiology
  • Protein Domains
  • Proteomics


  • Arabidopsis Proteins
  • Carrier Proteins
  • Phosphatidylinositols
  • AtMPK4 protein, Arabidopsis
  • Mitogen-Activated Protein Kinases