Figure 4 : Knockdown of CCT subunits impairs proteostasis of pluripotent stem cells.

From: Somatic increase of CCT8 mimics proteostasis of human pluripotent stem cells and extends C. elegans lifespan

Figure 4

(a) Western blot analysis of control and HD-iPSC lysates with antibodies to HTT and β-actin. Arrow indicates mutant polyQ-expanded HTT. The images are representative of three independent experiments. (b) In HD polyQ180-expressing iPSCs, the levels of mutant HTT are dramatically decreased compared with normal HTT copy. The expression of polyQ180 HTT was confirmed by using an antibody that detects polyQ-expanded mutant HTT. The images are representative of three independent experiments. (c) Filter trap analysis shows that HD-iPSCs do not have increased levels of polyQ aggregates compared with control iPSCs (detected by anti-polyQ-expansion diseases marker antibody). However, knockdown of a single CCT subunit triggers the accumulation of polyQ aggregates. The images are representative of three independent experiments. (d) Knockdown of different CCT subunits in HD polyQ71 iPSC line #1 results in a similar increase of polyQ aggregates. Right panel: SDS–PAGE analysis with antibodies to HTT and β-actin loading control. The images are representative of three independent experiments. (e) Knockdown of a single CCT subunit triggers the accumulation of polyQ aggregates in both polyQ71 iPSC line #2 and polyQ180 iPSCs. Right panel: polyQ-expansion diseases marker antibody was used to confirm that the total protein levels of mutant HTT do not change on knockdown of CCT subunits. The images are representative of two independent experiments.