We used monoclonal antibodies specific for acetylated and nonacetylated alpha-tubulin to detect and to localize microtubules containing acetylated alpha-tubulin (stable microtubules) in the pathogenic protozoa Tritrichomonas foetus and Trichomonas vaginalis. SDS-PAGE analysis showed that tubulin is a major protein of both parasites, being enriched in cytoskeletal preparations of whole cells extracted with Triton X-100. The monoclonal antibodies, which recognize all isoforms of alpha-tubulin (B-5-1-2) and only acetylated alpha-tubulin (6-11B-1), bind to the tubulin of T. foetus and T. vaginalis as seen by immunoblotting. Tubulin-containing structures were localized using immunofluorescence microscopy and transmission electron microscopy of the whole cytoskeleton previously incubated in the presence of the anti-tubulin antibodies and a second antibody-gold complex, and then processed using the negative staining or replica techniques. The results obtained indicate that, in addition to the flagellar microtubules, those which form the peltar-axostyle system represent stable microtubules containing acetylated alpha-tubulin.
Acetylation Animals