Potential roles for Kinesins at the cortical division site.

Elisabeth Lipka,Sabine Müller

doi:10.3389/fpls.2012.00158

Abstract

Spatial control of cytokinesis is critical for cell and plant morphology. The plane of cell division is established at G2/M transition and is initially demarcated at the cortex of the cell by the cytoskeletal preprophase band (PPB) and subsequently throughout mitosis by the cortical division zone (CDZ). Few kinesins, belonging to different classes of the superfamily, either display a distinct spatio-temporal localization at the PPB and CDZ, or genetic evidence proposes a specific function there. Protein phosphorylation and degradation are likely directing the cell cycle-dependent localization and activity of some of these kinesins, as indicated by mutation of respective conserved motifs. Furthermore, kinesins are required for continuous recruitment of CDZ identity markers to the CDZ. This review summarizes the limited current knowledge of kinesins potentially involved in the steps required for correctly oriented division planes, considering localization patterns and genetic evidence, and discussing kinesin function in context with interaction partners and cell cycle regulation.

Highlights

The cytoskeleton is a major facilitator of cell division and cell expansion in all organisms
Minute detail is known about the regulation of preprophase band (PPB) assembly; genes encoding MT nucleation factors TONNEAU (TON)1A and TON1B and a protein phosphatase PP2A subunit TON2/DCD1/ADD1 are strictly required for PPB formation in Arabidopsis, Physcomitrella and maize, respectively, since knockout mutants lack PPBs and exhibit mis-positioned division planes (Camilleri et al, 2002; Azimzadeh et al, 2008; Wright et al, 2009; Spinner et al, 2010)
The CDK consensus motif [S/T-P-x-K/R] was detected several times in PHRAGMOPLAST ORIENTING KINESIN (POK), in AtKinG (KCH) and a phosphorylation site was predicted for AtKINUa (Malcos and Cyr, 2011)

Summary

Elisabeth Lipka and Sabine Müller*

Cell and Developmental Genetics, Center for Plant Molecular Biology, University of Tuebingen, Tuebingen, Germany. The plane of cell division is established at G2/M transition and is initially demarcated at the cortex of the cell by the cytoskeletal preprophase band (PPB) and subsequently throughout mitosis by the cortical division zone (CDZ). Few kinesins, belonging to different classes of the superfamily, either display a distinct spatio-temporal localization at the PPB and CDZ, or genetic evidence proposes a specific function there. Protein phosphorylation and degradation are likely directing the cell cycle-dependent localization and activity of some of these kinesins, as indicated by mutation of respective conserved motifs. This review summarizes the limited current knowledge of kinesins potentially involved in the steps required for correctly oriented division planes, considering localization patterns and genetic evidence, and discussing kinesin function in context with interaction partners and cell cycle regulation

INTRODUCTION

Lipka and Müller