title: In vitro inhibition of tubulin assembly by a ribonucleoprotein complex associated with the free ribosome fraction isolated from Xenopus laevis oocytes: effect at the level of microtubule-associated proteins.
abstract: The 100 000 X g supernatant prepared from defolliculated Xenopus laevis oocytes inhibits, in a dose-dependent manner, the in vitro polymerization of rat brain neurotubulin. The oocyte inhibitory factor is thermolabile, totally inactivated by RNAse and partially by trypsin. A preliminary purification of the inhibitor showed that it is associated with the free oocyte ribosomes (80 S). The saturable binding of microtubule-associated proteins, essentially MAP2, to this 80 S ribonucleoprotein fraction is responsible for the inhibition of the in vitro tubulin assembly.
mesh_terms: D000818:Animals; D001921:Brain / Q000648:ultrastructure; D005260:Female; D008869:Microtubule-Associated Proteins / Q000502:physiology*; D008870:Microtubules / Q000648:ultrastructure*; D009865:Oocytes / Q000502:physiology*; D011485:Protein Binding; D051381:Rats; D012261:Ribonucleoproteins / Q000502:physiology*; D012270:Ribosomes / Q000502:physiology; D008941:Spindle Apparatus / Q000648:ultrastructure; D014404:Tubulin / Q000378:metabolism*; D029867:Xenopus Proteins / Q000502:physiology*; D014982:Xenopus laevis
chemical_list: C000603443:MAP2 protein, Xenopus; D008869:Microtubule-Associated Proteins; D012261:Ribonucleoproteins; D014404:Tubulin; D029867:Xenopus Proteins