Cellular distribution of NS4B carboxy terminal domain mutants and D-lactate dehydrogenase membrane binding domain in Huh7 cells. A. The panels on the right show Huh7 cells expressing different NS4B-CTD mutants or d-LDH membrane binding domain (d-LDH MBD) after 24 h. Expression constructs are shown in red. Using COX-IV as a marker protein, mitochondria are shown in middle panels and in merged picture in green. On the right a schematic view of the different NS4B-CTD mutants is drawn; in red the sequence of NS4B-CTD-wt, in black the mutations made and in green the exchanged amino acids from the membrane contacting helix of the d-LDH-MBD. B. Huh7 cells were co-transfected with NS4B-CTD-HA and d-LDH MBD-Myc and analyzed by immunofluorescence after 24 h of expression. The first panel shows d-LDH MBD, which is presented as red in the merged picture. NS4B-CTD is displayed in the second panel and is shown in the merged picture as green.