Distribution of non-class-III beta-tubulin isoforms in neuronal and non-neuronal cells.

beta-Tubulin isoforms in brain tissues and in cell lines were analyzed by high-resolution isoelectric focusing in combination with monoclonal antibodies. Post-translational modifications of brain non-class-III beta-tubulin isoforms were found in phylogenetically distant species ranging from pig to carp. Less extensive modifications were also observed in Neuro-2a, HeLa and 3T3 cells, where most acidic isoforms were glutamylated, while the basic, most abundant isoforms were not. The data suggest post-translational modification of non-class-III beta-tubulin isoforms in neuronal as well as in non-neuronal cells. Such modification might modulate interaction of tubulin with microtubule-associated proteins.