Aspartate mutations in PS1 or γ-secretase inhibitors do not prevent APP-PS1 FRET
| Condition | FRET donor FITC labeled | FRET acceptor Cy3 labeled | FITC lifetime (psec) mean ± SD |
|---|---|---|---|
| wt or D257A PS1 (control) | PS1 loop | None | 2600 ± 110 (n = 12) |
| wt PS1 | PS1 loop | APP 770 | 2290 ± 216** (n = 27) |
| wt PS1 | PS1 loop | APP 770 + DAPT | 2416 ± 118* (n = 9) |
| wt PS1 | PS1 loop | APP770 + WPE-111-31C | 1972 ± 264** (n = 30) |
| D257A PS1 | PS1 loop | APP770 | 2255 ± 264** (n = 26) |
The table shows summary data of the FLIM assay for PS1 loop-APP C-terminus proximity under baseline conditions and in the presence of manipulations to preclude APP γ-secretase cleavage. If there is no interaction, lifetimes on the order of ≈2600 psec are observed. If FRET is detected, a population with a statistically shorter lifetime (approximately < 2400 psec) is observed.
↵* p < 0.05,
↵** p < 0.01, compared with non-FRETing control.