title: Arabidopsis thaliana MAP65-1 and MAP65-2 function redundantly with MAP65-3/PLEIADE in cytokinesis downstream of MPK4.
abstract: Plant cytokinesis occurs by the growth of cell plates from the interior to the periphery of the cell. These dynamic events in cytokinesis are mediated by a plant-specific microtubule (MT) array called the phragmoplast, which consists of bundled antiparallel MTs between the two daughter nuclei. The NACK-PQR pathway, a NACK1 kinesin-like protein and mitogen activated protein kinase (MAPK) cascade, is a key regulator of plant cytokinesis through the regulation of phragmoplast MTs. The MT-associated protein MAP65 has been identified as one of the structural components of MT assays involved in cell division, and we recently showed that Arabidopsis AtMAP65-3/PLEIADE (PLE) is a substrate of MPK4 that is a component of the NACK-PQR pathway in Arabidopsis. Here we show that AtMAP65-1 and AtMAP65-2 are also phosphorylated by MPK4. AtMAP65-1 and AtMAP65-2 that localize to the phragmoplast were phosphorylated by MPK4 in vitro. Although mutants of the Arabidopsis AtMAP65-1 and AtMAP65-2 genes exhibited a wild-type phenotype, double mutations of AtMAP65-3 and AtMAP65-1 or AtMAP65-2 caused more severe growth and cytokinetic defects than the single atmap65-3/ple mutation. These results suggest that AtMAP65-1 and AtMAP65-2 also function in cytokinesis downstream of MPK4.
authors: Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan. msasabe@bio.nagoya-u.ac.jp
authors: Michiko
authors: M
authors: Sasabe
authors: Ken
authors: K
authors: Kosetsu
authors: Mikiko
authors: M
authors: Hidaka
authors: Akinori
authors: A
authors: Murase
authors: Yasunori
authors: Y
authors: Machida
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D048749:Cytokinesis; D035264:Flowers / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D010766:Phosphorylation; D018515:Plant Leaves / Q000235:genetics; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C572577:MAP65-2 protein, Arabidopsis; D008869:Microtubule-Associated Proteins; D012333:RNA, Messenger