TABLE 2.
Association of Gβ1γ2 dimer with phospholipid vesicles
Recombinant purified Gβ1γ2 dimers were incubated with phospholipid vesicles containing different amounts of anionic PS in the presence and absence of PI3Kγ variants. Phospholipid vesicles were prepared as detailed under “Experimental Procedures.” Aliquots of sedimented phospholipid vesicles and their supernatants were subjected to SDS/PAGE followed by immunoblotting using Gβ1–4-specific antiserum. Chemiluminescence signals were estimated with a VersaDocTM 4000 MP imaging system (Bio-Rad). For calculation of vesicle-associated Gβ1γ2, signal intensities in the sedimented phospholipid vesicles and its supernatant were added and considered as 100%. Shown here are the mean values ± S.E. of four separate experiments. PI3Kγ variants do not affect the association of Gβ1γ2 with phospholipid vesicles.
| Phospholipid vesicles | Coincubation of Gβ1γ2 with PI3Kγ variants | Phospholipid vesicle-associated Gβ1γ2 |
|---|---|---|
| % | ||
| +0 mm PS | p110γ | 57.2 ± 9.3 |
| p87–p110γ | 56.1 ± 8.6 | |
| p101–p110γ | 51.4 ± 9.9 | |
| +0.18 mm PS | p110γ | 59.5 ± 8.5 |
| p87–p110γ | 57.7 ± 10.4 | |
| p101–p110γ | 58.6 ± 9.2 | |
| +0.3 mm PS | p110γ | 57.8 ± 7.2 |
| p87–p110γ | 60.2 ± 9.7 | |
| p101–p110γ | 61.8 ± 7.7 |