Fig. 4

ABCA4 ΔAsp864_Gly885 shows significant activity and displays a subcellular localization in HEK293T cells similar to ABCA4 WT. A ATPase activity of wild-type ABCA4 (WT) and the ΔAsp864_Gly885 variants in the presence and absence of all-trans retinal (ATR) expressed as the percentage activity in the absence of ATR (basal activity). The data is shown as mean ± SEM, n = 3 for each construct and represents 3 independent experiments. B HEK293T cells were transfected with the ABCA4 plasmids, labeled for ABCA4 (red) and calnexin as an ER marker (green) and counterstained with DAPI nuclear stain (blue). The ΔAsp864_Gly885 variant is associated with intracellular vesicles, that resemble vesicles observed for WT ABCA4. A fraction of the truncated protein is retained in the ER