Figure 2.
Overexpression of the transcription factor NRF-1 induces apoptosis in serum-depleted cells. (A) Western analysis for three clones expressing the NRF-1-ER fusion protein. (B) Northern analysis of clones overexpressing NRF-1 over a time course of 24 h in the presence of 4-OHT and cycloheximide. (C) Immunoprecipitation with cytochrome c demonstrates increases in the level of cytochrome c protein synthesis in NRF-1-expressing cells under serum deprivation. Control and NRF-1 cell lysates were immunoprecipitated in the presence of mouse IgG conjugated to agarose or cytochrome c coupled to protein G-Sepharose. (D) PI FACS analysis indicating the percentage of sub-G1 cell populations found in three independently derived cell lines overexpressing NRF-1 after 24 h in 0.5% serum. Approximately 105 cells were analyzed in triplicate for each sample, and these results are representative of three separate experiments. (E) Electron microscopy analysis of cells from control and NRF-1-overexpressing cells after 8 h in 0.5% serum. Bars: left and middle panels, 2 μm; right panel, 200 nm.