The C-terminal variable region specifies the dynamic properties of Arabidopsis microtubule-associated protein MAP65 isotypes.

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.

Microtubules, MAPs and plant directional cell expansion.

Plant microtubules (MTs) polymerize and depolymerize in a process termed dynamic instability. This allows the assembly, reorganization, and disassembly of at least four MT arrays throughout the cell cycle. The cortical MT array lines the plasma membrane during interphase and plays a central role in directional cell expansion.

Arabidopsis NAP1 is essential for Arp2/3-dependent trichome morphogenesis.

The dynamic nature of the eukaryotic actin cytoskeleton is essential for the locomotion of animal cells and the morphogenesis of plant and fungal cells. The F-actin nucleating/branching activity of the Arp2/3 complex is a key function for all of these processes. The SCAR/WAVE family represents a group of Arp2/3 activators that are associated with lamellipodia formation.

The Arabidopsis microtubule-associated protein AtMAP65-1: molecular analysis of its microtubule bundling activity.

The 65-kD microtubule-associated protein (MAP65) family is a family of plant microtubule-bundling proteins. Functional analysis is complicated by the heterogeneity within this family: there are nine MAP65 genes in Arabidopsis thaliana, AtMAP65-1 to AtMAP65-9. To begin the functional dissection of the Arabidopsis MAP65 proteins, we have concentrated on a single isoform, AtMAP65-1, and examined its effect on the dynamics of mammalian microtubules.

The plant cytoskeleton: recent advances in the study of the plant microtubule-associated proteins MAP-65, MAP-190 and the Xenopus MAP215-like protein, MOR1.

The microtubule cytoskeleton is a dynamic filamentous structure involved in many key processes in plant cell morphogenesis including nuclear and cell division, deposition of cell wall, cell expansion, organelle movement and secretion. The principal microtubule protein is tubulin, which associates to form the wall of the tubule. In addition, various associated proteins bind microtubules either to anchor, cross-link or regulate the microtubule network within cells.