title: Arabidopsis microtubule-associated protein AtMAP65-2 acts as a microtubule stabilizer.
abstract: Nine genes that encode proteins of the MAP65 family have been identified in the Arabidopsis thaliana genome. In this study, we reported that AtMAP65-2, a member of the AtMAP65 family, could strongly stabilize microtubules (MTs). Bacterially-expressed AtMAP65-2 fusion proteins induced the formation of large MT bundles in vitro. Although AtMAP65-2 showed little effect on MT assembly or nucleation, AtMAP65-2 greatly stabilized MTs that were subjected to low-temperature treatment in vitro. Analyses of truncated versions of AtMAP65-2 indicated that the region that encompassed amino acids 495-578, which formed a flexible extended loop, played a crucial role in the stabilization of MTs. Analysis of suspension-cultured Arabidopsis cells that expressed the AtMAP65-2-GFP fusion protein showed that AtMAP65-2 co-localized with MTs throughout the cell cycle. Cortical MTs that were decorated with AtMAP65-2-GFP were more resistant to the MT-disrupting drug propyzamide and to ice treatment in vivo. The results of this study demonstrate that AtMAP65-2 strongly stabilizes MTs and is involved in the regulation of MT organization and dynamics.
authors.affiliation: Department of Plant Sciences, China Agricultural University, Beijing, 100193, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Li
authors.forename: Xian
authors.initials: X
authors.lastname: Zeng
authors.forename: Zi-Qiang
authors.initials: ZQ
authors.lastname: Liu
authors.forename: Qiu-Tao
authors.initials: QT
authors.lastname: Meng
authors.forename: Ming
authors.initials: M
authors.lastname: Yuan
authors.forename: Tong-Lin
authors.initials: TL
authors.lastname: Mao
mesh_terms: D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D003080:Cold Temperature; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D018613:Microscopy, Confocal; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D008870:Microtubules / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D008869:Microtubule-Associated Proteins; D049452:Green Fluorescent Proteins