Tubulin pools in differentiating neuroblastoma cells.
The distribution of tubulin in soluble, reversibly stabilized (assembled) and insoluble forms has been determined in neuroblastoma cells undergoing microtubule-dependent neurite elongation. Procedures were developed to obtain reproducible tubulin fractions and to assay total tubulin. Radioimmunoassays showed that both differentiated and nondifferentiated cell contained approximately 4 pg of tubulin per cell, of which 3-10% was in an insoluble, particulate form. The amount of tubulin assembled in differentiated cells was four to five times greater than in nondifferentiated cells, constituting 48-63% and 11-16% of the total tubulin pool in the respective cell types. Calculation of the concentration of soluble tubulin indifferentiated cells (approximately 0.8 mg/ml) and nondifferentiated cells (approximately 1.6 mg/ml) indicates that a critical concentration of subunits probably does not limit the induction of microtubule formation during neurite elongation.
D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D002999:Clone Cells; D003078:Colchicine / Q000494:pharmacology; D051379:Mice; D008870:Microtubules / Q000378:metabolism; D009447:Neuroblastoma; D009474:Neurons / Q000166:cytology* / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism*
D014404:Tubulin; D003078:Colchicine