Figure 3.

Overexpression of Gab1 reduces the requirement for NGF to prevent apoptosis. PC-12 cells were transfected with an expression vector containing the Gab1 cDNA. Two cell lines overexpressing Gab1, Tr. 7, and Tr. 16, and a vector-only transfectant (Control) were used. Cells were seeded in six-well dishes, grown for 2 days, then washed five times with serum free medium and incubated in serum free media containing the indicated amount of NGF or complete serum starvation. After 12 h, floating and adherent cells were harvested from which cytoplasmic DNA was prepared, electrophoresed on agarose gels and quantitated. (A) Overexpression of Gab1 enhances cell survival. Gel electrophoresis of cytoplasmic DNA from Control, Tr. 7, and Tr. 16 cell lines. (B) Quantitation of the relative amounts of cytoplasmic DNA released. Symbols are as follows: Tr. 7 (▪), Tr. 16 (▴), Control (⧫). Values shown are normalized to the DNA present in the 25 ng/ml sample and are the average of four or five independent experiments. Bars = SEM.