Figure 5.

Transformation of NIH3T3 cells by tP2YR is caused by coordinated activation of Gα_i and Gα_q. A. Gα_i and Gα_q cooperate and cause the appearance of transformed foci similar to those caused by tP2YR. NIH3T3 cells were transfected with pZIP-NeoSV(x)1 expression vectors encoding tP2YR or Mas, or co-transfected with vectors encoding constitutively activated mutants of Gα_I2(QL) and Gα_q(QL). The appearance of foci of transformed cells was monitored 3 weeks after transfection (40× magnification). B. Transformation by tP2YR and Mas requires Gα_i protein function. NIH3T3 cells were transfected with pZIP-NeoSV(X)1 expression vectors encoding H-Ras(61L) (25 ng per 60 mm dish), G2A (2 μg per dish), tP2YR (2 μg per dish) or Mas (1 μg per dish). Cultures were then maintained in growth medium (-) or medium supplemented with 100 ng per ml PTX (+) for 14 to 16 days after which the number of foci were quantitated. Data shown are expressed as the mean of the percent of the total number of foci in the untreated dishes ± standard error and are representative of two separate assays performed in triplicate.