(D) Effects of lysosomes on the degradation of Htt-552. PC12 cells were trasfected with Htt-552 as described above and cell lysates were incubated with isolated lysosomes. The degradation of Htt-552-18Q and Htt-552-100Q after incubating with intact lysosomes was assessed with Western blot analysis. Values are the mean±SE of three independent experiments. **P<0.01 (compared with Htt-552-18Q without treatment); ##P<0.01 (compared with Htt-552-100Q without treatment). 