Table 2. Comparison of the specificities of four GSK3 inhibitors.
Assays for each protein kinase were carried out at the ATP concentration specified, which approximates the Km value for each kinase. Each protein kinase used was expressed, purified and assayed as described previously [18,19]. The results shown are percentage activity compared with DMSO-only controls for each enzyme tested, and are means of duplicate determinations. Similar results were obtained in another independent experiment. Abbreviations: MKK, MAPK kinase; JNK, c-Jun N-terminal kinase; MAPKAP-K; MAPK-activated protein kinase; MSK, mitogen- and stress-activated kinase; PRAK, p38-regulated/activated kinase; PKA, cAMP-dependent protein kinase; ROCK, Rho-dependent kinase; AMPK, AMP-activated protein kinase; CHK, checkpoint kinase; PHK, phosphorylase kinase; LCK, lymphocyte kinase; CSK; C-terminal Src kinase; NEK, NIMA-related protein kinase.
| Activity (%) | |||||||
|---|---|---|---|---|---|---|---|
| Protein kinase | ATP (μM) | CT99021 (1 μM) | CT99021 (10 μM) | AR-AO144-18 (1 μM) | AR-AO144-18 (10 μM) | SB 216763 (10 μM) | SB 415286 (10 μM) |
| MKK1 | 5 | 102±3 | 67±4 | 84±8 | 84±8 | 66±4 | 28±8 |
| ERK2 | 50 | 89±3 | 90±4 | 100±7 | 103±5 | 82±5 | 75±9 |
| JNK | 20 | 78±5 | 73±1 | 96±7 | 80±4 | 95±9 | 96±8 |
| SAPK2a/p38α | 50 | 100±0 | 93±1 | 100±8 | 111±9 | 87±2 | 86±5 |
| SAPK2b/p38β2 | 20 | 80±5 | 91±5 | 95±3 | 99±2 | 79±2 | 89±3 |
| SAPK3/p38γ | 5 | 92±2 | 97±0 | 99±3 | 89±8 | 65±2 | 81±1 |
| SAPK4/p38δ | 5 | 86±5 | 84±3 | 91±5 | 86±4 | 81±5 | 92±2 |
| RSK1 | 50 | 91±0 | 80±5 | 109±2 | 108±5 | 31±3 | 14±4 |
| MAPKAP-K2 | 20 | 90±1 | 85±5 | 87±5 | 83±1 | 89±5 | 83±4 |
| MSK1 | 20 | 99±0 | 89±3 | 104±3 | 98±4 | 58±9 | 89±4 |
| PRAK | 20 | 82±1 | 72±7 | 92±6 | 100±3 | 79±1 | 87±7 |
| PKA | 20 | 87±5 | 98±3 | 89±7 | 101±7 | 91±0 | 94±2 |
| PKC | 20 | 90±4 | 85±7 | 93±2 | 90±5 | 30±7 | 30±0 |
| PDK1 | 20 | 91±4 | 88±8 | 105±0 | 105±8 | 85±3 | 74±4 |
| PKB | 5 | 94±5 | 67±0 | 95±6 | 81±4 | 53±1 | 79±2 |
| SGK | 20 | 101±8 | 59±7 | 94±8 | 79±0 | 82±4 | 45±4 |
| S6K1 | 20 | 123±3 | 111±4 | 97±5 | 119±5 | 109±5 | 119±1 |
| GSK3b | 5 | 3±0 | 1±1 | 6±1 | 1±1 | 1±0 | 1±0 |
| ROCK-II | 20 | 96±1 | 82±5 | 102±1 | 84±6 | 76±5 | 78±5 |
| AMPK | 50 | 90±8 | 71±2 | 96±4 | 89±1 | 64±3 | 21±0 |
| CHK1 | 20 | 90±3 | 82±2 | 110±8 | 107±4 | 49±5 | 53±7 |
| CK2 | 5 | 96±6 | 74±4 | 86±5 | 87±3 | 90±0 | 85±7 |
| PHK | 50 | 96±3 | 86±1 | 73±3 | 75±8 | 77±77 | 84±0 |
| LCK | 50 | 88±2 | 83±4 | 94±2 | 95±6 | 64±3 | 65±5 |
| CSK | 20 | 88±5 | 96±4 | 107±5 | 101±1 | 96±4 | 88±4 |
| CDK2–cyclin A | 20 | 78±9 | 13±8 | 86±3 | 45±1 | 14±2 | 6±2 |
| CK1 | 20 | 90±7 | 89±8 | 95±7 | 91±9 | 84±4 | 78±6 |
| DYRK1a | 50 | 87±3 | 81±1 | 91±8 | 78±3 | 6±0 | 8±2 |
| NEK6 | 50 | 89±2 | 98±6 | 103±1 | 91±3 | 91±3 | 93±4 |
| NEK2a | 50 | 109±3 | 84±6 | 90±1 | 93±6 | 91±1 | 111±6 |