Acetylated alpha-tubulin in Trypanosoma cruzi: immunocytochemical localization

Abstract

We have used monoclonal antibodies specific for acetylated and non-acetylated alpha-tubulin to localize microtubules containing acetylated alpha-tubulin in all developmental forms of the life cycle of Trypanosoma cruzi. This was demonstrated using immunofluorescence and by transmission electron microscopy of thin sections, negative stained cells, and replicas of whole Triton X-100 extracted cells immunolabeled with antibody-gold complex. The antibody specific for acetylated alpha-tubulin (6-11B-1) binds to the flagellar, as well as to the sub-pellicular microtubules. The extent of labeling of the sub-pellicular microtubules with the monoclonal antibody recognized alpha-acetylated tubulin was smaller than that observed with the antibody which recognizes all tubulin isoforms. In relation to the developmental forms, the extent of labeling of the microtubules with antibody 6-11B-1 was larger in epimastigote and trypomastigote than in amastigote forms. Incubation of the parasites for 1 h at 0 degrees C or in the presence of either colchicine or vinblastine did not interfere with the sub-pellicular microtubules. These observations, in agreement with those reported for Trypanosoma brucei brucei (Schneider et al., 1987; Schulze et al., 1987; Sasse & Gull, 1988) indicate that the sub-pellicular microtubules of trypanosomatids represent stable microtubules containing acetylated alpha-tubulin (or the alpha 3-tubulin isotype).

Trypanosoma cruzi Bromodomain Factor 3 Binds Acetylated α-Tubulin and Concentrates in the Flagellum during Metacyclogenesis

“…Multiple tubulin isotypes are present in microtubules, due to a series of posttranslational modifications. Among all isoforms of ␣-tubulin associated with the T. cruzi subpellicular and axonemal microtubules, the acetylated form seems to be predominant (10). Isolated subpellicular microtubules and flagellar complexes were obtained from epimastigotes and trypomastigotes in order to verify the presence of TcBDF3 in these cellular components.…”

“…In trypanosomatids, acetylated ␣-tubulin is found in the subpellicular microtubules and in the flagella of T. cruzi and Trypanosoma brucei (10,11). This PTM is also present in the ephemeral microtubules of the mitotic spindle of T. brucei (11).…”

Experimental chemotherapy for Chagas disease: 15 years of research contributions from in vivo and in vitro studies

“…To date, no major alterations have been reported in both sub-pellicular and flagellar microtubules of T. cruzi treated with microtubule-targeting drugs such as taxol, colchicine and vinblastine. This may be a consequence of the high content of acetylated tubulin and/or poly-glutamylation of tubulin that is present in these parasites (Souto-Padron et al 1993. Since these structures in trypanosomatids are very resistant to microtubule disrupters compared to the microtubule structures in mammalian cells, they may represent interesting targets for drug development and deserve further investigation.…”

Contributions of Ultrastructural Studies to the Cell Biology of Trypanosmatids: Targets for Anti-Parasitic Drugs

“…The number of microtubules varies in different regions of the body of the parasite, but they are regularly spaced and connected by filaments to each other, to the inner face of the plasma membrane and to cytoplasmic organelles, such as the endoplasmic reticulum. One of the characteristics of the sub-pellicular microtubules is their high proportion of acetylated and/or polyglutamylated tubulins, which make them very stable [100]. Although actin and actin-binding proteins have been characterized in trypanosomatids, in T. cruzi they do not seem to be associated with sub-pellicular microtubules, as observed in Leishmania [101].…”