Research Paper Volume 7, Issue 2 pp 133—143

Figure 4. MAF1 overexpression extends the short lifespan due to PKA hyperactivation. (A) MAF1 overexpression by using a high copy number plasmid increases the protein amount. sch9Δbcy1Δ cells expressing Myc-tagged Maf1 from low copy (pRS313) or high copy centrimeric plasmid (pRS423) were cultured to stationary phase and protein samples were prepared for western blot analysis. (B) Quantification shows around 6-fold increase in Maf1 protein expression in pRS423. (C) MAF1 overexpression extends chronological lifespan of short-lived bcy1Δ mutant but not WT. WT and bcy1Δ cells without or with MAF1 overexpression were cultured to stationary phase and the fractions of survival over indicated time points were measured by colony forming assay. Error bars stands for the SEM of 3 replicates. ns, not significant, **p < 0.001. (D) MAF1 overexpression partially rescues the extended lifespan of sch9Δ mutant in sch9Δbcy1Δ cells. sch9Δ cells and sch9Δbcy1Δ cells without and with MAF1 overexpression were cultured to stationary phase and the fractions of survival over indicated time points were measured by colony forming assay. Error bars stands for the SEM of 3 replicates, ***p < 0.0001.