The association of glycosomal enzymes and microtubules: a physiological phenomenon or an experimental artifact?
Subpellicular microtubules isolated from Trypanosoma brucei parasites were fractionated on a phosphocellulose column, and the trypanosomal p52 microtubule-associated protein was eluted along with two other proteins of 41 and 36 kDa. These proteins were found to be the glycosomal enzymes aldolase (41 kDa) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH, 36 kDa) by enzyme activity, antibody cross-reaction, and N-terminal sequencing. These enzymes were coprecipitated with tubulin in the presence of taxol, and aldolase had the capacity to polymerize tubulin and crosslink microtubules. Immunolocalization of anti-aldolase and anti-GAPDH antibodies did not show an interaction between these enzymes and the subpellicular microtubules. The question whether the copurification of aldolase and the subpellicular microtubules could reflect a physiological phenomenon or may be an experimental artifact is discussed.
Balaban
N
N
Department of Membrane Research, Weizmann Institute of Science, Rehovot, Israel.
Goldman
R
R
D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D002458:Cell Fractionation; D004586:Electrophoresis / Q000379:methods; D005634:Fructose-Bisphosphate Aldolase / Q000302:isolation & purification / Q000378:metabolism*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000302:isolation & purification / Q000378:metabolism*; D007150:Immunohistochemistry; D008830:Microbodies / Q000201:enzymology*; D008854:Microscopy, Electron; D008869:Microtubule-Associated Proteins / Q000302:isolation & purification / Q000378:metabolism; D008870:Microtubules / Q000737:chemistry / Q000187:drug effects / Q000201:enzymology*; D017239:Paclitaxel; D011233:Precipitin Tests; D014346:Trypanosoma brucei brucei / Q000201:enzymology* / Q000648:ultrastructure; D014404:Tubulin / Q000302:isolation & purification / Q000378:metabolism
D000470:Alkaloids; D000972:Antineoplastic Agents, Phytogenic; D008869:Microtubule-Associated Proteins; D014404:Tubulin; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D005634:Fructose-Bisphosphate Aldolase; D017239:Paclitaxel