Fig. 5. An intact CNBD is specifically involved in trafficking of HERG. (A) Immunoblot performed on HEK cells expressing cDNAs encoding HERG_wt and HERG_750-870. (B) HL-1 cardiac, PC12 neuronal and Cos7 kidney cells transfected with the indicated constructs and subjected to immunoblotting. (C) Immunocytochemical analyses of cells permeabilized with Triton X-100. Staining was performed with an anti-HA antibody followed by incubation with a secondary antibody conjugated with Oregon Green. Punctate staining of the HERG_wt channel is absent from cells transfected with HERG_750-870. (D) Cells expressing the HERG_750-870 construct were treated with PK followed by immunoblotting. (top) The membrane was blotted with an anti-HA antibody, stripped and reprobed for CASK (bottom). Signal intensities before and after PK treatment were measured and quantified. (E) Immunoblot of cell extracts expressing HERG_26-135 and HERG_750-870 mutant channels. Membrane was probed with an anti-HERG antibody.