FIG. 1.

Overproduction of GFP-Ttll6Ap causes elongation of glutamyl side chains on tubulin in vivo. (A) Western blots of total proteins from GFP-Ttll6Ap-expressing cells that are either uninduced (0 h) or induced for 1, 2, or 4 h with either 1 or 2.5 μg of CdCl₂/ml. (B and C) 2D silver-stained protein gels containing cytoskeletons of uninduced (B) or induced (C) GFP-Ttll6Ap cells. The arrows point at strings of highly acidic protein isoforms that appear at the mass level of the main spots of α- and β-tubulin upon induction of GFP-Ttll6Ap. (D to E) Confocal fluorescence images of the GFP signal in growing (D) and cilia regenerating (E) GFP-Ttll6Ap cells induced with 2.5 μg of CdCl₂/ml for 3 h. Note the increase of the signal of GFP-Ttll6Ap in short growing cilia (arrowheads) and on subcortical microtubules (arrows). Bar, 10 μm.