Fig. 5. Detyrosinated MTs decrease EF-mediated motility. (A) NO₂Tyr inhibits Glu MT elaboration. Incubation of 3T3 cells with (NO₂Tyr; a,c) or without (control, b,d) NO₂Tyr, which inhibits the formation of Glu MTs (a,b) without altering the total MT network (c,d) or the stable, acetylated MTs (Chang et al., 2002) (not shown). Scale bar, 10 µm. (B) Cells lacking Glu MTs migrate more rapidly in the EF. Average motility speed (µm hour^-1) of NO₂Tyr-treated 3T3 cells in a 6 V cm^-1 EF (1.5 hours) was significantly greater than control cells (marked with ^*; P<0.05). At least 20 cells were quantified in each of three experiments.