Figure 5.

Chaperones are recruited into HD exon 1 aggregates. HDQ83 expression was induced by removal of doxycycline from the culture medium. Three days after induction of HDQ83, expression cells were double immunolabeled with antibodies directed against BiP and HDQ83 (a–c). Double immunolabeling of cells with antibodies directed against Hsp70/HDQ83 (d–f) and Hsp40/HDQ83 (g–i) was performed on day 6 after induction of HDQ83 expression. HDQ83 protein aggregates were immunolabeled with anti-CAG53b coupled to FITC-conjugated secondary antibody (green); chaperones were labeled with antibodies directed against BiP, Hsp70, and Hsp40 coupled to a CY3-conjugated secondary antibody (red). Nuclei were counterstained with Hoechst. Colocalization of HDQ83 aggregates with BiP, Hsp70, and Hsp40 is shown in c, f, and i, respectively. Bar, 5 μm.