title: Arabidopsis TONNEAU1 proteins are essential for preprophase band formation and interact with centrin.
abstract: Plant cells have specific microtubule structures involved in cell division and elongation. The tonneau1 (ton1) mutant of Arabidopsis thaliana displays drastic defects in morphogenesis, positioning of division planes, and cellular organization. These are primarily caused by dysfunction of the cortical cytoskeleton and absence of the preprophase band of microtubules. Characterization of the ton1 insertional mutant reveals complex chromosomal rearrangements leading to simultaneous disruption of two highly similar genes in tandem, TON1a and TON1b. TON1 proteins are conserved in land plants and share sequence motifs with human centrosomal proteins. The TON1 protein associates with soluble and microsomal fractions of Arabidopsis cells, and a green fluorescent protein-TON1 fusion labels cortical cytoskeletal structures, including the preprophase band and the interphase cortical array. A yeast two-hybrid screen identified Arabidopsis centrin as a potential TON1 partner. This interaction was confirmed both in vitro and in plant cells. The similarity of TON1 with centrosomal proteins and its interaction with centrin, another key component of microtubule organizing centers, suggests that functions involved in the organization of microtubule arrays by the centrosome were conserved across the evolutionary divergence between plants and animals.
authors.affiliation: Institut Jean-Pierre Bourgin, Station de Génétique et d'Amélioration des Plantes UR254, Institut National de la Recherche Agronomique, Centre de Versailles, F-78000 Versailles, France.
authors.forename: Juliette
authors.initials: J
authors.lastname: Azimzadeh
authors.forename: Philippe
authors.initials: P
authors.lastname: Nacry
authors.forename: Anna
authors.initials: A
authors.lastname: Christodoulidou
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Drevensek
authors.forename: Christine
authors.initials: C
authors.lastname: Camilleri
authors.forename: Nardjis
authors.initials: N
authors.lastname: Amiour
authors.forename: François
authors.initials: F
authors.lastname: Parcy
authors.forename: Martine
authors.initials: M
authors.lastname: Pastuglia
authors.forename: David
authors.initials: D
authors.lastname: Bouchez