Table 1.
Effect of phosphorylation by PKA on anti-capping activity of wild-type VASP and VASP mutant proteins
| +10μM profilin
|
||||
|---|---|---|---|---|
| VASP protein | mock | PKA-treated | mock | PKA-treated |
| Wild-type VASP | 1.1 | 0.6 | 1.5 | 0.5 |
| VASP-S153A | 1.2 | 0.6 | 1.8 | 0.5 |
| VASP-S235A | 1.1 | 0.7 | 1.4 | 0.9 |
| VASP-T274A | 1.2 | 0.7 | 1.8 | 0.8 |
| VASP-S153A,S235A | 1.4 | 1.1 | 1.7 | 1.4 |
| VASP-S153A,T274A | 1.2 | 0.7 | 1.6 | 0.7 |
| VASP-S235A,T274A | 1.2 | 1.0 | 1.6 | 1.2 |
| VASP-S153A,S235A,T274A | 1.2 | 1.0 | 1.6 | 1.4 |
Tabulated are the relative initial rates of actin assembly obtained in anti-capping reactions containing mock-treated VASP proteins or PKA-treated VASP proteins. Reactions were carried out in the presence and absence of 10μM profilin as indicated. Data are normalized to the initial rate obtained with the PKA-treated VASP triple mutant (VASP-S153A, S235A, T274A) in the absence of profilin. The relative initial rate observed with reactions containing capping protein in the absence of VASP was 0.5.