IQ67 DOMAIN proteins facilitate preprophase band formation and division-plane orientation

Nat Plants. 2021 Jun;7(6):739-747. doi: 10.1038/s41477-021-00923-z. Epub 2021 May 24.

Abstract

Spatiotemporal control of cell division is essential for the growth and development of multicellular organisms. In plant cells, proper cell plate insertion during cytokinesis relies on the premitotic establishment of the division plane at the cell cortex. Two plant-specific cytoskeleton arrays, the preprophase band (PPB) and the phragmoplast, play important roles in division-plane orientation and cell plate formation, respectively1. Microtubule organization and dynamics and their communication with membranes at the cortex and cell plate are coordinated by multiple, mostly distinct microtubule-associated proteins2. How division-plane selection and establishment are linked, however, is still unknown. Here, we report members of the Arabidopsis IQ67 DOMAIN (IQD) family3 as microtubule-targeted proteins that localize to the PPB and phragmoplast and additionally reside at the cell plate and a polarized cortical region including the cortical division zone (CDZ). IQDs physically interact with PHRAGMOPLAST ORIENTING KINESIN (POK) proteins4,5 and PLECKSTRIN HOMOLOGY GTPase ACTIVATING (PHGAP) proteins6, which are core components of the CDZ1. The loss of IQD function impairs PPB formation and affects CDZ recruitment of POKs and PHGAPs, resulting in division-plane positioning defects. We propose that IQDs act as cellular scaffolds that facilitate PPB formation and CDZ set-up during symmetric cell division.

MeSH terms

  • Arabidopsis / cytology*
  • Arabidopsis / genetics
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Dinitrobenzenes
  • Gene Expression Regulation, Plant
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Microtubules / drug effects
  • Microtubules / metabolism
  • Mutation
  • Nicotiana / genetics
  • Phylogeny
  • Plant Cells / drug effects
  • Plant Cells / metabolism
  • Plants, Genetically Modified
  • Prophase
  • Protein Domains
  • Sulfanilamides
  • Vesicular Transport Proteins / metabolism

Substances

  • Arabidopsis Proteins
  • Dinitrobenzenes
  • POK protein, Arabidopsis
  • Sulfanilamides
  • Vesicular Transport Proteins
  • Green Fluorescent Proteins
  • oryzalin