Abstract
Plant cytokinesis is accomplished with the formation of phragmoplast, which is formed between two daughter chromatins during anaphase of mitosis. The development of phragmoplast is shown to be regulated by the MAP kinase cascade. Although the MAP65, one of microtubule binding protein, was recently shown to be phosphorylated by MAPK, however, most of targets are unidentified. We applied the phosphoprotein purification with immobilized metal ion affinity chromatography and two-dimensional difference in gel electrophoresis for the identification of the phosphorylated targets of MAP kinase cascade in Arabidopsis. We identified PATL2, GAPD, lectin like protein as candidate of target of MAP kinase and found that some of them were phosphorylated by MAPK in vitro. The PATL2 is a member of SEC14 family protein and speculated to be involved in membrane trafficking. These results suggest that MAPK cascade regulate membrane trafficking concomitant with expansion of phragmoplast.
