Fig. 7.

Expression of DN DP1 suppresses the death of cultured cortical neurons treated with camptothecin. Control viruses for each vector were generated by removal of the start codon from the insert. F denotes that the protein has a FLAG epitope attached to the C terminal. Effects of expression of (Δ1–126) DN DP1, a dominant-negative mutant containing an N-terminal truncation from amino acids 1–126 (A), (Δ103–126) DN DP1F, a FLAG-tagged dominant-negative mutant containing a DNA-binding domain deletion of amino acids 103–126 (B), (Δ233–272) DP1F, a FLAG-tagged mutant containing the E2F-binding domain deletion of amino acids 233–272 (C), and WT DP1 and respective controls (D) on the survival of cortical neurons after camptothecin treatment for 1 d. A, Graph in which each point is the mean ± SEM of combined data from three independent experiments (each independent experiment performed in triplicate) and is expressed relative to the number of neurons present in each culture at the initial time of camptothecin (10 μm) treatment. B—D, Representative experiments in which each point is the mean ± SEM of three cultures from the same experimental trial. Similar results (B–D) were obtained in two independent experiments.