RRC ID 4032
Author Smertenko AP, Kaloriti D, Chang HY, Fiserova J, Opatrny Z, Hussey PJ.
Title The C-terminal variable region specifies the dynamic properties of Arabidopsis microtubule-associated protein MAP65 isotypes.
Journal Plant Cell
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.
Volume 20(12)
Pages 3346-58
Published 2008-12
DOI 10.1105/tpc.108.063362
PII tpc.108.063362
PMID 19060108
PMC PMC2630438
MeSH Arabidopsis / genetics Arabidopsis / metabolism Arabidopsis Proteins / chemistry* Arabidopsis Proteins / genetics Arabidopsis Proteins / metabolism* Immunoblotting Microscopy, Confocal Microtubule-Associated Proteins / chemistry* Microtubule-Associated Proteins / genetics Microtubule-Associated Proteins / metabolism* Microtubules / metabolism* Plant Proteins / chemistry* Plant Proteins / genetics Plant Proteins / metabolism* Protein Binding / genetics Protein Isoforms / chemistry Protein Isoforms / genetics Protein Isoforms / metabolism* Recombinant Proteins / chemistry Recombinant Proteins / genetics Recombinant Proteins / metabolism
IF 8.228
Times Cited 45
Arabidopsis / Cultured plant cells, genes pda08789 pda09605