Table 1.
CFP fluorescent lifetimes and CFP/YFP Förster efficiency in dual-tagged GluA2-CFP/YFP receptors
| Receptor | FP donor | FP acceptor | τCFP,† ns | n | E,‡ % |
| GluA2-0Y-6C | CFP | YFP | 3.45 ± 0.02 | 11 | 0 |
| GluA2-0A-6C | CFP | amber | 3.44 ± 0.01 | 10 | — |
| GluA2-0Y-10C | CFP | YFP | 3.43 ± 0.05 | 8 | 0 |
| GluA2-0A-10C | CFP | amber | 3.46 ± 0.04 | 10 | — |
| GluA2-3Y-6C | CFP | YFP | 3.38 ± 0.03 | 11 | 0 |
| GluA2-3A-6C | CFP | amber | 3.45 ± 0.01 | 8 | — |
| GluA2-3Y-10C | CFP | YFP | 3.43 ± 0.03 | 14 | 0 |
| GluA2-3A-10C | CFP | amber | 3.42 ± 0.03 | 7 | — |
| GluA2-6Y-10C | CFP | YFP | 3.05 ± 0.02* | 14 | 13.4 |
| GluA2-6A-10C | CFP | amber | 3.52 ± 0.03 | 10 | — |
| GluA2-6C-10Y | CFP | YFP | 3.10 ± 0.03 | 8 | 10.6 |
| GluA2-6C | CFP | — | 3.46 ± 0.03 | 8 |
E, FRET efficiency; ns, nanoseconds.
*
P < 0.05 compared with the corresponding amber-containing receptor.
†
Fluorescence lifetime for CFP was obtained by FLIM analysis as described in Materials and Methods in the presence of YFP or the FRET-incapable YFP variant amber. Data represent the mean ± SEM of the average lifetime observed in n different cells.
‡
FRET efficiency for intrareceptor FRET in GluA2-CFP/YFP receptors was calculated from the values of τCFP obtained in presence and absence of YFP as described in Materials and Methods.