Figure 1.

Locations of the Cys mutations of PS1 used in this study. Schematic diagram of human PS1. Endogenous Cys that were replaced with Ser in PS1/Cys(−) are shown as black circles. Amino acid residues substituted to Cys in this and previous studies are shown as circles with their single-letter character representing the original amino acids. Residues analyzed in this study are shown as yellow circles. Residues in which Cys substitution resulted in a loss of γ-secretase activity are shown as gray circles. Catalytic aspartates are shown as yellow stars.