FIGURE 3: TC-1 protects against pro-apoptotic genes.

(A) Yeast cells harbouring control plasmid (Vector) or plasmids expressing different pro-apoptotic peptides including NUC1, AIF, YCA1 or YBH3 were co-transformed with either empty plasmid (Vector) or a plasmid expressing TC-1 or 14-3-3. The spot growth assay was used to assess the growth of the transformants on YNB media with galactose alone (Control) or with a sublethal concentration of copper sulfate (CuSO₄). The cells were allowed to grow at 30°C for 3 days and photographs of the plates are shown.

(B) Freshly growing cultures of yeast transformants with two empty vectors (Control), one empty vector and a YCA1 expressing plasmid (YCA1) or the YCA1 and the TC-1 expressing plasmids (YCA1+TC-1) were challenged without (-) or with (+) sublethal Yca1p activating levels of copper (CuSO₄). Viability was determined by microscopical examination of at least 300 cells. The data is shown as the percentage of cells that survive and represents the median ± SEM of at least n = 3 independent experiments. * indicates that the viability of cells expressing YCA1 alone was significantly lower than the viability of control cells while ** indicates that the viability of cells expressing YCA1+TC-1 was significantly higher than the viability of cells expressing YCA1 alone with P-values < 0.05.