title: Putative RopGAPs impact division plane selection and interact with kinesin-12 POK1.
abstract: Cell shape is defined by the surrounding cell walls in plants. Thus, spatial control over cell division planes and cell expansion polarity are essential to maintain cell morphology. In eukaryotes, cell polarity and expansion are controlled by Rho GTPase signalling, regulating cytoskeletal reorganization and vesicle trafficking(1). However, until now, Rho signalling was not implicated in mitotic events in plants. Here, we report a pair of putative Rho GTPase activating proteins (RhoGAPs) that interact with the mitosis-specific kinesin-12 POK1, a core component of the cortical division zone/site (CDZ/CDS) that is required for division plane maintenance in Arabidopsis(2-4). The designated pleckstrin homology GAPs (PHGAPs) are cytoplasmic and plasma membrane associated in interphase, but during mitosis they additionally localize to the CDZ/CDS in a POK-dependent manner. In contrast to pok1 pok2 mutants, phgap1 phgap2 double mutants show moderate cell wall positioning defects as a consequence of inaccurate positioning of the cortical division zone marker POK1. We conclude that loss of PHGAP function interferes with division plane selection in proliferative cell divisions.
authors: Developmental Genetics, Centre for Plant Molecular Biology (ZMBP), University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany.
authors: Dorothee
authors: D
authors: Stöckle
authors: Developmental Genetics, Centre for Plant Molecular Biology (ZMBP), University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany.
authors: Arvid
authors: A
authors: Herrmann
authors: Developmental Genetics, Centre for Plant Molecular Biology (ZMBP), University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany.
authors: Elisabeth
authors: E
authors: Lipka
authors: Developmental Genetics, Centre for Plant Molecular Biology (ZMBP), University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany.
authors: Theresa
authors: T
authors: Lauster
authors: Developmental Genetics, Centre for Plant Molecular Biology (ZMBP), University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany.
authors: Richard
authors: R
authors: Gavidia
authors: Developmental Genetics, Centre for Plant Molecular Biology (ZMBP), University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany.
authors: Steffi
authors: S
authors: Zimmermann
authors: Developmental Genetics, Centre for Plant Molecular Biology (ZMBP), University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany.
authors: Sabine
authors: 0000-0003-1467-3217
authors: S
authors: Müller
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D016764:Cell Polarity; D048430:Cell Shape; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism; D016547:Kinesins / Q000235:genetics* / Q000378:metabolism; D008938:Mitosis; D021381:Protein Transport
chemical_list: D029681:Arabidopsis Proteins; D020690:GTPase-Activating Proteins; C085379:rho GTPase-activating protein; C413766:PAKRP1 protein, Arabidopsis; C511453:POK1 protein, Arabidopsis; C525051:Pakrp1l protein, Arabidopsis; D016547:Kinesins