Figure 1
From: The controversial role of Sirtuins in tumorigenesis — SIRT7 joins the debate
SIRT7 suppresses expression of tumor suppressor genes by locus-specific deacetylation of H3K18Ac at promoter regions. SIRT7 complexes with ELK4 to deacetylate H3K18 at the promoters of a select set of tumor suppressor genes, such as NME1, COPS2, thus repressing target gene expression. SIRT7 may also complex with other as yet undetermined transcriptional proteins (shown as “??”) to deacetylate histone H3K18Ac at promoters of the ribosomal protein gene, RPS7, RPS14, RPS20, which can function as tumor suppressor genes in hematopoietic malignancy, and repress their gene expression. Previously described effects of SIRT7 are also represented. SIRT7 can connect chromatin remodeling complexes with the RNA Pol I machinery required for rDNA driving ribosome biogenesis in dividing cells6. SIRT7 is also reported to deacetylate p53, and promote cell survival3, although this effect needs further confirmation.
