The C-Terminal Variable Region Specifies the Dynamic Properties of Arabidopsis Microtubule-Associated Protein MAP65 Isotypes

Andrei P. Smertenko, Despina Kaloriti, Hsin-Yu Chang, Jindriska Fiserova, Zdenek Opatrny, Patrick J. Hussey*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

55 Citations (Scopus)

Abstract

The microtubule-associated protein, MAP65, is a member of a family of divergent microtubule-associated proteins from different organisms generally involved in maintaining the integrity of the central spindle in mitosis. The dicotyledon Arabidopsis thaliana and the monocotyledon rice (Oryza sativa) genomes contain 9 and 11 MAP65 genes, respectively. In this work, we show that the majority of these proteins fall into five phylogenetic clades, with the greatest variation between clades being in the C-terminal random coil domain. At least one Arabidopsis and one rice isotype is within each clade, indicating a functional specification for the C terminus. In At MAP65-1, the C-terminal domain is a microtubule binding region (MTB2) harboring the phosphorylation sites that control its activity. The At MAP65 isotypes show differential localization to microtubule arrays and promote microtubule polymerization with variable efficiency in a MTB2-dependent manner. In vivo studies demonstrate that the dynamics of the association and dissociation of different MAP65 isotypes with microtubules can vary up to 10-fold and that this correlates with their ability to promote microtubule polymerization. Our data demonstrate that the C-terminal variable region, MTB2, determines the dynamic properties of individual isotypes and suggest that slower turnover is conditional for more efficient microtubule polymerization.

Original languageEnglish
Pages (from-to)3346-3358
Number of pages13
JournalThe Plant Cell
Volume20
Issue number12
DOIs
Publication statusPublished - Dec 2008

Keywords

  • FISSION YEAST
  • BINDING
  • PHRAGMOPLAST
  • SUPPRESSION
  • IDENTIFICATION
  • CYTOKINESIS
  • CYTOSKELETON
  • PLANTS
  • IN-VIVO
  • TOBACCO BY-2 CELLS

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