title: Dynamic regulation of cortical microtubule organization through prefoldin-DELLA interaction.
abstract: Plant morphogenesis relies on specific patterns of cell division and expansion. It is well established that cortical microtubules influence the direction of cell expansion, but less is known about the molecular mechanisms that regulate microtubule arrangement. Here we show that the phytohormones gibberellins (GAs) regulate microtubule orientation through physical interaction between the nuclear-localized DELLA proteins and the prefoldin complex, a cochaperone required for tubulin folding. In the presence of GA, DELLA proteins are degraded, and the prefoldin complex stays in the cytoplasm and is functional. In the absence of GA, the prefoldin complex is localized to the nucleus, which severely compromises α/β-tubulin heterodimer availability, affecting microtubule organization. The physiological relevance of this molecular mechanism was confirmed by the observation that the daily rhythm of plant growth was accompanied by coordinated oscillation of DELLA accumulation, prefoldin subcellular localization, and cortical microtubule reorientation.
authors.affiliation: Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, Ingeniero Fausto Elio s/n, 46022 Valencia, Spain.
authors.forename: Antonella
authors.initials: A
authors.lastname: Locascio
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Blázquez
authors.forename: David
authors.initials: D
authors.lastname: Alabadí
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000254:growth & development / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D002453:Cell Cycle; D002455:Cell Division; D005875:Gibberellins / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism*; D018832:Molecular Chaperones / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D010937:Plant Growth Regulators / Q000378:metabolism*; D014026:Nicotiana / Q000166:cytology / Q000502:physiology; D014404:Tubulin / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C109555:GAI protein, Arabidopsis; D005875:Gibberellins; D018832:Molecular Chaperones; D009687:Nuclear Proteins; D010937:Plant Growth Regulators; D014404:Tubulin; C112806:prefoldin