title: Tubulins in Trichomonas vaginalis: molecular characterization of alpha-tubulin genes, posttranslational modifications, and homology modeling of the tubulin dimer.
abstract: We have isolated and analysed an alpha-tubulin-encoding gene (atub1) in an early-diverging eukaryote, Trichomonas vaginalis. The complete atub1 open reading frame included 1.356 bp encoding a polypeptide of 452 amino-acyl residues. A second alpha-tubulin gene (atub2) was amplified by PCR using primers derived from consensus alpha-tubulin amino acid sequences. Both T. vaginalis alpha-tubulin sequences showed high identity to those described in other parabasalids (94.4%-97.3%), and exhibited a high degree of similarity to sequences from Metazoa (such as pig brain) and diplomonads (such as Giardia). Despite large evolutionary distances previously observed between trichomonads and mammals, the three-dimensional model of the T. vaginalis tubulin dimer was very similar to that of pig brain. Possible correlations between alpha-tubulin sequences and posttranslational modifications (PTMs) were examined. Our observations corroborated previous data obtained in T. vaginalis using specific anti-PTMs antibodies. As described in the related species Tritrichomonas mobilensis, microtubules are likely acetylated, non-tyrosinated, glutamylated, and non-glycylated in T. vaginalis. Evolutionary considerations concerning the time of appearance of these tubulin PTMs are also discussed since trichomonads are potentially one of the earliest diverging eukaryotic lineages.
authors.affiliation: Institut Pasteur, INSERM U547, Lille, France.
authors.forename: C
authors.initials: C
authors.lastname: Noël
authors.forename: D
authors.initials: D
authors.lastname: Gerbod
authors.forename: N M
authors.initials: NM
authors.lastname: Fast
authors.forename: R
authors.initials: R
authors.lastname: Wintjens
authors.forename: P
authors.initials: P
authors.lastname: Delgado-Viscogliosi
authors.forename: W F
authors.initials: WF
authors.lastname: Doolittle
authors.forename: E
authors.initials: E
authors.lastname: Viscogliosi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D001921:Brain; D019281:Dimerization; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013552:Swine; D014246:Trichomonas vaginalis / Q000235:genetics* / Q000378:metabolism*; D014404:Tubulin / Q000737:chemistry / Q000235:genetics
chemical_list: D014404:Tubulin