ANQ/AtMKK6 of Arabidopsis thaliana involved in cytokinesis is activated by the HINKEL-ANP and activate group B MAPKs

Abstract

ANQ/MAPKK6 of Arabidopsis thaliana regulates cytokinesis. anq mutant plants exhibit cytokinesis defect. ANQ was expressed preferentially in proliferating tissues. ANQ localized at the equatorial plane of phragmoplast. We showed that ANQ acts as a MAPKK in yeast when it was co-expressed with HINKEL/AtNACK1 kinesin-like protein and ANP1 (and ANP3) MAP kinase kinase kinase. We identified MAPKs of group B as downstream factor of ANQ with in vitro phopholylation and activation experiment and with yeast two-hybrid analysis. These results proposed that HINKEL-ANP1 (and ANP3)-ANQ-group B MAPK constitute a MAPK cascade. We will discuss the role of this cascade in Arabidopsis cytokinesis.