title: The carboxy-terminal sequence Asp427-Glu432 of beta-tubulin plays an important function in axonemal motility.
abstract: Flagellar motility is the result of specific interactions between axonemal microtubular proteins and the dynein motors. Tubulin, the main component of microtubule, is a very polymorphic protein resulting from the expression of several isogenes and from the existence of various post-translational modifications. In order to characterize tubulin isoforms and tubulin domains that are important for flagellar movement, we prepared monoclonal antibodies against axonemal proteins from whole sea-urchin sperm tails. The monoclonal antibodies obtained were screened for their potency to inhibit demembranated-reactivated sperm models and for their monospecific immunoreactivity on immunoblot. Among the different antibodies we obtained, D66 reacted specifically with a subset of beta-tubulin isoforms. Limited proteolysis, HPLC, peptide sequencing, mass spectroscopy and immunoblotting experiments indicated that D66 recognized an epitope localized in the primary sequence Gln423-Glu435 of the C-terminal domain of Lytechinus pictus beta2-tubulin, and that this sequence belongs to class IVb. The use of synthetic peptides and immunoblotting analysis further narrowed the amino acids important for antibody recognition to Asp427-Glu432. Because the primary effect of this antibody on sperm motility is to decrease the flagellar beat frequency, we suggest that this sequence is involved in the tubulin-dynein head interaction.
authors: Urology Research Laboratory, McGill University, Royal Victoria Hospital, Montreal, Quebec, Canada.
authors: S
authors: S
authors: Audebert
authors: D
authors: D
authors: White
authors: J
authors: J
authors: Cosson
authors: P
authors: P
authors: Huitorel
authors: B
authors: B
authors: Eddé
authors: C
authors: C
authors: Gagnon
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology; D012617:Sea Urchins; D017386:Sequence Homology, Amino Acid; D013081:Sperm Motility / Q000187:drug effects / Q000502:physiology*; D014404:Tubulin / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*
chemical_list: D000911:Antibodies, Monoclonal; D010446:Peptide Fragments; D014404:Tubulin