Figure 1

Schematic representation of PS1 structure. In this model, PS1 is depicted to traverse the membrane eight times. Each circle represents an amino acid, and shaded circles represent individual residues mutated in FAD cases. In addition to point mutations, two deletion mutations ⊗I83/M84 and ⊗S290–S319 have been identified. Arrow marks the major site of endoproteolytic cleavage, which occurs when nascent PS1 molecule assembles with nicastrin, APH-1 and PEN-2.