title: Posttranslational modifications in the C-terminal tail of axonemal tubulin from sea urchin sperm.
abstract: After proteolytic digestion of sperm tubulin from sea urchin Paracentrotus lividus, C-terminal peptides were isolated by chromatographic separations. The peptides were analyzed by Edman degradation and matrix-assisted laser desorption/ionization-time of flight mass spectrometry. About 70% of the isolated C-terminal peptides were unmodified. The remaining modified peptides have undergone a combination of numerous posttranslational modifications generating significant heterogeneity of sperm tubulin. alpha-Tubulin is modified by detyrosylation, release of the penultimate glutamate, polyglutamylation, and polyglycylation. Glycylation and glutamylation can coexist within one alpha-tubulin isoform. beta-Tubulin undergoes polyglycylation but was not observed to be polyglutamylated. The number of units posttranslationally added reaches 11 and 12 glycyl units on beta- and alpha-tubulin, respectively. This is different from the polyglycylation of axonemal tubulin in Paramecium cilia where up to 40 added glycyl units were observed both on alpha- and beta-tubulin.
authors.affiliation: Laboratoire de Neurobiologie de la Diversité Cellulaire, CNRS URA 2054, ESPCI, 10 rue Vauquelin, 75231 Paris cedex 5, France.
authors.forename: J
authors.initials: J
authors.lastname: Mary
authors.forename: V
authors.initials: V
authors.lastname: Redeker
authors.forename: J P
authors.initials: JP
authors.lastname: Le Caer
authors.forename: J
authors.initials: J
authors.lastname: Rossier
authors.forename: J M
authors.initials: JM
authors.lastname: Schmitter
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D008401:Gas Chromatography-Mass Spectrometry; D005971:Glutamates / Q000378:metabolism; D005998:Glycine / Q000378:metabolism; D008297:Male; D008870:Microtubules / Q000378:metabolism*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D011499:Protein Processing, Post-Translational; D013082:Sperm Tail / Q000378:metabolism*; D014404:Tubulin / Q000378:metabolism*
chemical_list: D005971:Glutamates; D010446:Peptide Fragments; D014404:Tubulin; D005998:Glycine