title: Mutations of tubulin glycylation sites reveal cross-talk between the C termini of alpha- and beta-tubulin and affect the ciliary matrix in Tetrahymena.
abstract: Two types of polymeric post-translational modifications of alpha/beta-tubulin, glycylation and glutamylation, occur widely in cilia and flagella. Their respective cellular functions are poorly understood. Mass spectrometry and immunoblotting showed that two closely related species, the ciliates Tetrahymena and Paramecium, have dramatically different compositions of tubulin post-translational modifications in structurally identical axonemes. Whereas the axonemal tubulin of Paramecium is highly glycylated and has a very low glutamylation content, the axonemal tubulin of Tetrahymena is glycylated and extensively glutamylated. In addition, only the alpha-tubulin of Tetrahymena undergoes detyrosination. Mutations of the known glycylation sites in Tetrahymena tubulin affected the level of each polymeric modification type in both the mutated and nonmutated subunits, revealing cross-talk between alpha- and beta-tubulin. Ultrastructural analyses of glycylation site mutants uncovered defects in the doublet B-subfiber of axonemes and revealed an accumulation of dense material in the ciliary matrix, reminiscent of intraflagellar transport particles seen by others in Chlamydomonas. We propose that polyglycylation and/or polyglutamylation stabilize the B-subfiber of outer doublets and regulate the intraflagellar transport.
authors.affiliation: Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris, Laboratoire de Neurobiologie, UMR 7637 CNRS, 10 rue Vauquelin, 75005 Paris, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Redeker
authors.forename: Nicolette
authors.initials: N
authors.lastname: Levilliers
authors.forename: Emilie
authors.initials: E
authors.lastname: Vinolo
authors.forename: Jean
authors.initials: J
authors.lastname: Rossier
authors.forename: Danielle
authors.initials: D
authors.lastname: Jaillard
authors.forename: Dylan
authors.initials: D
authors.lastname: Burnette
authors.forename: Jacek
authors.initials: J
authors.lastname: Gaertig
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Bré
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002923:Cilia / Q000378:metabolism / Q000648:ultrastructure; D020409:Molecular Motor Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D010247:Paramecium / Q000378:metabolism / Q000648:ultrastructure; D011499:Protein Processing, Post-Translational; D013768:Tetrahymena / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D014404:Tubulin / Q000235:genetics / Q000378:metabolism*
chemical_list: D020409:Molecular Motor Proteins; D014404:Tubulin