Figure 1.

SIRT1 as an epigenetic regulator and DNA repair response modulator. SIRT1 contributes to heterochromatin formation and can be associated with transcriptionally repressed repetitive DNA loci (1); upon stress, SIRT1 can be dissociated from these regions towards the DNA damage site, resulting in chromatin reorganization which favors transcriptional changes (2); SIRT1 recruits epigenetic machinery to the transcriptional silencing around the DNA damage site (3); SIRT1 also participates in the recruitment and deacetylation of DDR (4) and DNA repair proteins, (5) helping in many steps of repair pathways.