p53-Induced Growth Arrest Is Regulated by the Mitochondrial SirT3 Deacetylase
Figure 3
The NAD+ -dependent Sir2 -like mitochondria protein deacetylase, SirT3, rescues EJ-p53 from p53 –inducible growth arrest.
The human SirT3 2.9 kb cDNA identified in the retroviral screen (Fig. 2) was placed in the MSCV retroviral plasmid using a bicistronic cassette with GFP (Green fluorescent protein). EJ-p53 cells were transduced with MSCV particles containing only GFP, mouse c-myc and human SirT3. Cell growth kinetics were determined by laser scanning florescence microscopy (A) and by monitoring cell populations (B). (C) [3H]-thymidine incorporation studies were assayed after 72 hours in EJ-p53 cells following transduction with indicated retroviruses followed by induction of p53 expression by tetracycline withdrawal for 72 hours. (D) SA-β galactosidase activity were determined in retroviral transduced EJ-p53 with MSCV-GFP/Sirt3 transduced into EJ-p53 cells prior and following induction of p53 by tetracycline withdrawal.