TABLE 1.
Homopolyarginine insertion rectifies the functional defect of a mutant deleting the RNA binding and NLS domain of Rev in a context-sensitive manner
| Rev–MS-C fusion protein | In vitro RNA bindinga
|
trans-Activationb (SD)
|
||
|---|---|---|---|---|
| RRE | MS2 | RRE | RREZ-MS2 | |
| Rev | +++++ | +++++ | 100 | 1.3 (0.7) |
| Rev–MS-C | +++++ | +++++ | 143 (9.7) | 114 (14.8) |
| Δ35/50Rev-i-9R/MS-C | +++++ | +++++ | 97 (14.5) | 122 (16.7) |
| Δ3-19Δ35-50Rev-i-9R/ MS-C | +++ | +++++ | 57 (7.5) | 89 (11.7) |
| Δ35-50Rev-i-9R & ter 87/MS-C | ++++ | +/− | 79 (11.5) | 0.6 (0.4) |
| Δ3-19Δ35-50Rev-i-9R & ter 87/MS-C | +++ | +/− | 38 (6.8) | 1.1 (0.3) |
| Δ35/50Rev/MS-C-i-9R | +/− | ++++ | 3.8 (1.7) | 2.2 (0.8) |
| Rev[(R)4WRE/DLRE]/ MS-C-i-9R | +/− | ++++ | 1.2 (0.8) | 4.7 (1.3) |
a
RNA binding was evaluated by EMSA at fixed levels for the respective RNAs but various levels of the individual proteins, expressed in E. coli as MBP fusion proteins. The binding potential of mutants is expressed as: ++++, 75%; +++, 50%; ++, 25%; +, 1%; and +/−, <0.5% of wt Rev or Rev–MS-C.
b
Mean GAG expression values from five experiments, normalized for transfection efficiency, are tabulated with the respective standard deviations. The positive values are denoted by boldface.