title: Polyglycylation of tubulin is essential and affects cell motility and division in Tetrahymena thermophila.
abstract: We analyzed the role of tubulin polyglycylation in Tetrahymena thermophila using in vivo mutagenesis and immunochemical analysis with modification-specific antibodies. Three and five polyglycylation sites were identified at glutamic acids near the COOH termini of alpha- and beta-tubulin, respectively. Mutants lacking all polyglycylation sites on alpha-tubulin have normal phenotype, whereas similar sites on beta-tubulin are essential. A viable mutant with three mutated sites in beta-tubulin showed reduced tubulin glycylation, slow growth and motility, and defects in cytokinesis. Cells in which all five polyglycylation sites on beta-tubulin were mutated were viable if they were cotransformed with an alpha-tubulin gene whose COOH terminus was replaced by the wild-type COOH terminus of beta-tubulin. In this double mutant, beta-tubulin lacked detectable polyglycylation, while the alpha-beta tubulin chimera was hyperglycylated compared with alpha-tubulin in wild-type cells. Thus, the essential function of polyglycylation of the COOH terminus of beta-tubulin can be transferred to alpha-tubulin, indicating it is the total amount of polyglycylation on both alpha- and beta-tubulin that is essential for survival.
authors.affiliation: Department of Cellular Biology, University of Georgia, Athens, Georgia 30602-2607, USA.
authors.forename: L
authors.initials: L
authors.lastname: Xia
authors.forename: B
authors.initials: B
authors.lastname: Hai
authors.forename: Y
authors.initials: Y
authors.lastname: Gao
authors.forename: D
authors.initials: D
authors.lastname: Burnette
authors.forename: R
authors.initials: R
authors.lastname: Thazhath
authors.forename: J
authors.initials: J
authors.lastname: Duan
authors.forename: M H
authors.initials: MH
authors.lastname: Bré
authors.forename: N
authors.initials: N
authors.lastname: Levilliers
authors.forename: M A
authors.initials: MA
authors.lastname: Gorovsky
authors.forename: J
authors.initials: J
authors.lastname: Gaertig
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D002455:Cell Division / Q000502:physiology; D002465:Cell Movement / Q000502:physiology*; D002470:Cell Survival / Q000502:physiology; D002923:Cilia / Q000502:physiology; D006031:Glycosylation; D018613:Microscopy, Confocal; D008870:Microtubules / Q000378:metabolism; D020409:Molecular Motor Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D016296:Mutagenesis / Q000502:physiology; D010641:Phenotype; D016808:Tetrahymena thermophila / Q000166:cytology* / Q000235:genetics / Q000378:metabolism; D014404:Tubulin / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D020409:Molecular Motor Proteins; D014404:Tubulin