title: Suppression of tubulin detyrosination by parthenolide recruits the plant-specific kinesin KCH to cortical microtubules.
abstract: Detyrosination of α-tubulin seems to be conserved in all eukaryotes. However, its biological function in plants has remained obscure. A conserved C-terminal tyrosine is removed by a still unidentified tubulin-tyrosine carboxypeptidase (TTC) and can be religated by a tubulin-tyrosine ligase (TTL). To obtain insight into the still elusive biological function of this detyrosination-tyrosination cycle, the effects of the TTC inhibitor parthenolide were analysed in BY-2 tobacco cells. Parthenolide caused a depletion of detyrosinated α-tubulin, whereas the level of tyrosinated tubulin was elevated. This biochemical effect was accompanied by growth inhibition in cycling BY-2 cells and alteration of microtubule-dependent events that define division and expansion geometry such as cell plate alignment or axial expansion. Furthermore, parthenolide triggered an apoplastic alkalinization indicative of activation of defence-related calcium influx channels. At the same time, parthenolide promoted the association of the plant-specific kinesin KCH with cortical microtubules. These observations are integrated into a working model, where detyrosination acts as signal to modulate the binding of kinesin motors involved in structural and sensory functions of the microtubular cytoskeleton.
authors.affiliation: Botanical Institute, Molecular Cell Biology, Karlsruhe Institute of Technology, Kaiserstraße 2, D-76131 Karlsruhe, Germany.
authors.forename: Natalie
authors.initials: N
authors.lastname: Schneider
authors.affiliation: Botanical Institute, Molecular Cell Biology, Karlsruhe Institute of Technology, Kaiserstraße 2, D-76131 Karlsruhe, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Ludwig
authors.affiliation: Botanical Institute, Molecular Cell Biology, Karlsruhe Institute of Technology, Kaiserstraße 2, D-76131 Karlsruhe, Germany peter.nick@kit.edu.
authors.forename: Peter
authors.initials: P
authors.lastname: Nick
mesh_terms: D002268:Carboxypeptidases / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D002478:Cells, Cultured; D017930:Genes, Reporter; D016547:Kinesins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D010453:Peptide Synthases / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D012717:Sesquiterpenes / Q000378:metabolism*; D014026:Nicotiana / Q000166:cytology / Q000378:metabolism*; D014404:Tubulin / Q000235:genetics / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D012717:Sesquiterpenes; D014404:Tubulin; C039520:tyrosine-tubulin; C002669:parthenolide; D014443:Tyrosine; D002268:Carboxypeptidases; C023212:tyrosyltubulin carboxypeptidase; D016547:Kinesins; D010453:Peptide Synthases; C023213:tyrosyltubulin ligase
keywords: KCH kinesin; microtubules; parthenolide; tobacco BY-2; tubulin detyrosination.