Effects of MAF1 Repression on Cell Viability
Cell growth and function are limited by nutrient availability. The Maf1 protein is an important regulator of RNA polymerase III (Pol III) that integrates nutrient availability with Pol III activity. When dephosphorylated, the Maf1 protein binds to Pol III, preventing expression of tRNA genes. Excess levels of tRNA have been associated with tumors (Orioli et al., 2016). Here, we hypothesized that MAF1 is essential for cell survival and that knockout of MAF1 would destabilize the cell. Using an shRNA approach, we targeted MAF1 function. Following Maf1 knockdown, we observed an increase in mitochondria membrane potential and in reactive oxygen species, both of which suggests an increase in cell instability. Interestingly, when these mitochondria were visualized using a green florescence protein directed to the mitochondria, we noted what appeared to be “ghost cells” in which mitochondria appeared disrupted. In summary, we demonstrated that knocking out MAF1 results in abnormal mitochondria activity and cell instability.
Orioli A., Praz V., Lhôte P., Hernandex N. (2016). Human MAF1 targets and represses active RNA polymerase III genes by preventing recruitment rather than inducing long-term transcriptional arrest. Genome Research 26: 624-635.
Cell growth and function are limited by nutrient availability. The Maf1 protein is an important regulator of RNA polymerase III (Pol III) that integrates nutrient availability with Pol III activity. When dephosphorylated, the Maf1 protein binds to Pol III, preventing expression of tRNA genes. Excess levels of tRNA have been associated with tumors (Orioli et al., 2016). Here, we hypothesized that MAF1 is essential for cell survival and that knockout of MAF1 would destabilize the cell. Using an shRNA approach, we targeted MAF1 function. Following Maf1 knockdown, we observed an increase in mitochondria membrane potential and in reactive oxygen species, both of which suggests an increase in cell instability. Interestingly, when these mitochondria were visualized using a green florescence protein directed to the mitochondria, we noted what appeared to be “ghost cells” in which mitochondria appeared disrupted. In summary, we demonstrated that knocking out MAF1 results in abnormal mitochondria activity and cell instability.
Orioli A., Praz V., Lhôte P., Hernandex N. (2016). Human MAF1 targets and represses active RNA polymerase III genes by preventing recruitment rather than inducing long-term transcriptional arrest. Genome Research 26: 624-635.