Figure 8.

(a) An alignment of a putative sequence motif that are both acetylated and SUMO1 conjugated. This sequence motif is based on this study on the crosstalk between acetylation of K487 and SUMO1 conjugation at K490 of PML, the known acetylated peptide sequences that contain KXXK,¹⁶ and the well-established SUMOylation motif, KXE. Note that some acetylated peptides contain KXK sequence (data not shown), and hence potentially KXKXE is a loosely conserved motif. (b) Proposed model summarizing the findings of this study. In HeLa cervical cancer cells, PML, SIRT1, and SIRT5 are predominantly localized in the cytoplasm, where PML is acetylated by HATs and deacetylated by SIRT1 and SIRT5. H₂O₂ induce nuclear translocation of PML, SIRT1, and SIRT5. Deacetylation of PML ac-K487 by SIRT1 or SIRT5 is required for H₂O₂-induced SUMO1 conjugation of PML K490, formation of PML-NBs, and cell death