title: Tubulin biosynthesis in the developmental cycle of a parasitic protozoan, Leishmania mexicana: changes during differentiation of motile and nonmotile stages.
abstract: Cytodifferentiation in the transition cycle of the parasitic protozoan Leishmania mexicana amazonensis was studied in vitro. The flagellated motile promastigotes transform into the nonmotile amastigotes in 7 days at 35 degrees C intracellularly in the murine macrophage line J774G8. In medium 199 plus fetal bovine serum, the reverse transformation occurs extracellularly at 27 degrees C in 2 days. Slab gel electrophoresis of leishmanias labeled with [35S]methionine during transformation revealed changes in protein banding patterns. The intensity of two protein species with apparent molecular weights of approximately equal to 55,000 increased in the amastigote-to-promastigote differentiation and decreased during the reverse transformation. These two protein species comigrated approximately with alpha- and beta-tubulin of Chlamydomonas flagella in two-dimensional gel electrophoresis. The lower band was further identified as beta-tubulin by immunoprecipitation using rabbit antiserum specific to the beta-tubulin of Chlamydomonas axonemes. The biosynthetic change of tubulin was found to correlate with the morphological change of microtubules is leishmanial flagella and cytoskeleton during transformation.
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D005786:Gene Expression Regulation; D007891:Leishmania / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D008970:Molecular Weight; D009068:Movement; D013997:Time Factors; D014404:Tubulin / Q000096:biosynthesis*
chemical_list: D014404:Tubulin