Function of the p86 subunit of eukaryotic initiation factor (iso)4F as a microtubule-associated protein in plant cells.

The isozyme form of eukaryotic initiation factor 4F [eIF-(iso)4F] from wheat germ is composed of a p28 subunit that binds the 7-methylguanine cap of mRNA and a p86 subunit having unknown function. The p86 subunit was found to have limited sequence similarity to a kinesin-like protein encoded by the katA gene of Arabidopsis thaliana. Native wheat germ eIF-(iso)4F and bacterially expressed p86 subunit and p86-p28 complex bound to taxol-stabilized maize microtubules (MTs) in vitro.

Competitive Inhibition of High-Affinity Oryzalin Binding to Plant Tubulin by the Phosphoric Amide Herbicide Amiprophos-Methyl.

Amiprophos-methyl (APM), a phosphoric amide herbicide, was previously reported to inhibit the in vitro polymerization of isolated plant tubulin (L.C. Morejohn, D.

Unique functional characteristics of the polymerization and MAP binding regulatory domains of plant tubulin.

An understanding of the regulation of microtubule polymerization and dynamics in plant cells requires biochemical information on the structures, functions, and molecular interactions of plant tubulin and microtubule-associated proteins (MAPs) that regulate microtubule function. We have probed the regulatory domain and polymerization domain of purified maize tubulin using MAP2, an extensively characterized mammalian neuronal MAP. MAP2 bound to the surface of preformed, taxol-stabilized maize microtubules, with binding saturation occurring with one MAP2 molecule per five to six tubulin dimers, as it does with mammalian microtubules.

Characterization of the reversible taxol-induced polymerization of plant tubulin into microtubules.

Taxol has been reported to induce the polymerization of plant tubulin into microtubules, albeit weakly when compared to that of mammalian tubulin [Morejohn, L.C., & Fosket, D.