FIG 1.

KIF1A protein undergoes rapid accumulation and degradation in neuronal cells upon MG132 and CHX treatments. (A) Differentiated PC12 cells were treated with the translation inhibitor cycloheximide, proteasome inhibitor MG132, or both cycloheximide and MG132 for 2, 4, 6, or 8 h. Cells were harvested at the indicated time points and lysates were analyzed by Western blotting to monitor protein levels of KIF1A, KIF5, KIF3A, and actin. (B to D) KIF1A, KIF5, and KIF3A protein levels were measured by band intensities and normalized to actin protein levels for each time point. Normalized values were again normalized to those of mock-infected 0-h samples. Values are means plus SEMs (error bars) from three independent experiments. n.s., not statistically significant. **, P < 0.01; ***, P < 0.001; ****, P < 0.0001 for the indicated comparison at 8 h posttreatment.