title: The Phragmoplast-Orienting Kinesin-12 Class Proteins Translate the Positional Information of the Preprophase Band to Establish the Cortical Division Zone in Arabidopsis thaliana.
abstract: The preprophase band (PPB) is a faithful but transient predictor of the division plane in somatic cell divisions. Throughout mitosis the PPBs positional information is preserved by factors that continuously mark the division plane at the cell cortex, the cortical division zone, by their distinct spatio-temporal localization patterns. However, the mechanism maintaining these identity factors at the plasma membrane after PPB disassembly remains obscure. The pair of kinesin-12 class proteins PHRAGMOPLAST ORIENTING KINESIN1 (POK1) and POK2 are key players in division plane maintenance. Here, we show that POK1 is continuously present at the cell cortex, providing a spatial reference for the site formerly occupied by the PPB. Fluorescence recovery after photobleaching analysis combined with microtubule destabilization revealed dynamic microtubule-dependent recruitment of POK1 to the PPB during prophase, while POK1 retention at the cortical division zone in the absence of cortical microtubules appeared static. POK function is strictly required to maintain the division plane identity factor TANGLED (TAN) after PPB disassembly, although POK1 and TAN recruitment to the PPB occur independently during prophase. Together, our data suggest that POKs represent fundamental early anchoring components of the cortical division zone, translating and preserving the positional information of the PPB by maintaining downstream identity markers.
authors: Center for Plant Molecular Biology, ZMBP, Developmental Genetics, University of Tübingen, 72076 Tübingen, Germany.
authors: Elisabeth
authors: E
authors: Lipka
authors: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors: Astrid
authors: A
authors: Gadeyne
authors: Center for Plant Molecular Biology, ZMBP, Developmental Genetics, University of Tübingen, 72076 Tübingen, Germany.
authors: Dorothee
authors: D
authors: Stöckle
authors: Center for Plant Molecular Biology, ZMBP, Developmental Genetics, University of Tübingen, 72076 Tübingen, Germany.
authors: Steffi
authors: S
authors: Zimmermann
authors: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors: Geert
authors: G
authors: De Jaeger
authors: Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305.
authors: David W
authors: DW
authors: Ehrhardt
authors: School of Biological Sciences, Illinois State University, Normal, Illinois 61790.
authors: Viktor
authors: V
authors: Kirik
authors: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors: Daniel
authors: D
authors: Van Damme
authors: Center for Plant Molecular Biology, ZMBP, Developmental Genetics, University of Tübingen, 72076 Tübingen, Germany sabine.mueller@zmbp.uni-tuebingen.de.
authors: Sabine
authors: S
authors: Müller