Table 1.

Effect of HSV-Gα* subunits on GTPγS-stimulated cyclic AMP accumulation in membranes from PTX-treated NS20Y-D2Lcells

ConditioncAMP accumulation (pmol·mg−1·min−1)
BasalForskolin (30 μm)+ GTPγS (1 μm)Stimulation1-a (% of forskolin)
Control8.8  ± 3.7178  ± 39355  ± 50*239  ± 60
HSV-Gαo6.8  ± 2.1186  ± 45246  ± 71134  ± 15
HSV-Gαi111.6  ± 2.5272  ± 70259  ± 36112  ± 19
HSV-Gαi29.0  ± 1.5292  ± 96261  ± 63118  ± 32
HSV-Gαi310.0  ± 2.7191  ± 43197  ± 48101  ± 3
HSV-LacZ12.7  ± 2.3175  ± 43313  ± 53*200  ± 27
  • NS20Y-D2L cells were infected with individual PTX-resistant Gα subunits (Gα*) for 18 hr and treated with PTX (500 ng/ml) for 4 hr. The medium was removed, and membranes were prepared for adenylate cyclase assays as described in Materials and Methods. cAMP accumulation was stimulated with forskolin (30 μm) in the absence and presence of GTPγS (1 μm). Data shown for basal, forskolin, and forskolin + GTPγS are expressed as pmol·mg−1·min−1 and are the mean ± SE of five independent experiments, assayed in duplicate.

  • F1-a Stimulation was calculated as the percentage of forskolin-stimulated cyclic AMP accumulation in the presence of GTPγS divided by cAMP accumulation with forskolin alone.

  • *p < 0.01 compared with forskolin alone (Student’st test).