Table 2.
Akt enzyme activity comparison in vitro and in COS-7 cells
Enzyme activity determined biochemically is given as a percentage of the maximally active ppAkt1. +, agonist-evoked enzyme activity in cells; 0, no detectable activity; ND, not determined.
| Akt1 sites |
Akt1 activity |
||
|---|---|---|---|
| 308 | 473 | In vitro | In cell |
| % | % | ||
| pThr | pSer | 100 | + |
| Thr | Ser | <1 | ND |
| pThr | Ser | 27 | ND |
| pThr | Asp | 24 | + |
| pThr | Glu | 15 | + |
| pThr | Ala | 9 | + |
| Thr | pSer | 5 | ND |
| Asp | pSer | 10 | 0 |
| Glu | pSer | ND | 0 |
| Ala | pSer | <0.001 | 0 |
| pSer | pSer | ND | +a |
| pSer | Ser | 1 | ND |
| pSer | Ala | ND | +a |
| Thr | Asp | <1 | ND |
| Thr | Glu | <1 | ND |
| Asp | Ser | <1 | ND |
| Glu | Ser | <1 | ND |
a A reduced response was observed compared with WT when the Akt1 mutant indicated was expressed at a reduced level, similar to the level of endogenous Akt (Fig. 3B).