Microtubules in Plants

Abstract

Microtubules (MTs) are highly conserved polar polymers that are key elements of the eukaryotic cytoskeleton and are essential for various cell functions. αβ-tubulin, a heterodimer containing one structural GTP and one hydrolysable and exchangeable GTP, is the building block of MTs and is formed by the sequential action of several molecular chaperones. GTP hydrolysis in the MT lattice is mechanistically coupled with MT growth, thus giving MTs a metastable and dynamic nature. MTs adopt several distinct higher-order organizations that function in cell division and cell morphogenesis. Small molecular weight compounds that bind tubulin are used as herbicides and as research tools to investigate MT functions in plant cells. The de novo formation of MTs in cells requires conserved γ-tubulin-containing complexes and targeting/activating regulatory proteins that contribute to the geometry of MT arrays. Various MT regulators and tubulin modifications control the dynamics and organization of MTs throughout the cell cycle and in response to developmental and environmental cues. Signaling pathways that converge on the regulation of versatile MT functions are being characterized.

Evolutionary Cell Biology of Proteins from Protists to Humans and Plants

“…). In this work, we have made similar observations with drugs directed against plant microtubules (Hashimoto ). Thus, sensitivities do not follow a strict scheme in mono‐ and bikonts.…”

“…When we tested cell division activity of P. tetraurelia cells in the presence of drugs with established depolymerizing effects in mammalian cells, colchicine, for example, exerted no effect in concentrations~1,000 times above those normally applied to mammalian cells (Pape et al 1991). In this work, we have made similar observations with drugs directed against plant microtubules (Hashimoto 2015). Thus, sensitivities do not follow a strict scheme in mono-and bikonts.…”

Affinity Purification and Characterization of Functional Tubulin from Cell Suspension Cultures of Arabidopsis and Tobacco

“…The acetylation of a-tubulin Lys-40 is catalyzed by a-tubulin acetyltransferase (aTAT), which is a homolog of MEC-17 in animals (Akella et al, 2010). Since MEC-17 homologs are absent in fungi and plants (Akella et al, 2010) and plant cells generally lack highly stable MTs (Hashimoto, 2015), it is puzzling how plant cells catalyze this conserved tubulin modification and whether acetylated MTs represent stable and long-lived MT subpopulations in plant cells as well. Overexpression of a nonacetylatable Lys-40-to-Arg a-tubulin mutant does not affect the morphology and development of Arabidopsis plants (Xiong et al, 2013).…”

“…In plants, MTs have important functions in essential cellular processes, such as cell division, and in cell morphogenesis. MTs in plant cells adopt several distinct higher order arrays and are remodeled in response to the cell cycle, developmental programs, and environmental cues (Hashimoto, 2015). Genetic, molecular, and cell biological approaches have been used to identify cellular factors that regulate the organization and dynamics of plant MTs.…”

Plant synthetic biology for molecular engineering of signalling and development

“…Plant cytoskeleton and motor proteins are intimately coupled with plant cell division, cell elongation, cell shape and polarity specification 64–66 . For example, cortical microtubules position the cellulose synthase complex, and thereby determine the site of cellulose microfibril deposition 67,68 .…”