Abstract
We explored the role of NAT10 acetyltransferase in the DNA damage response, focusing on its impact on 3D-genome architecture and DNA repair proteins. Compared to NAT10 wild-type (wt), NAT10 deficiency reduced XPC, DDB2, and p53 protein levels. In TP53 double-null (dn) cells, the NAT10 protein was undetectable, and DDB2 was significantly down-regulated. Although NAT10 depletion caused DDB2 down-regulation, it did not affect the DNA repair functions of the DDB2 protein. To this fact, protein interaction analysis revealed that UVC exposure weakens the DDB2-p53 interaction while strengthening the bond between NAT10 and DDB2. Also, AlphaFold 3 prediction tools showed a more potent interaction between DDB2 and p53 than DDB2 and NAT10 proteins implying that NAT10 rather regulates the DDB2-p53 protein complex. These proteomic NAT10-dependent changes coincided with alterations in chromatin interactions, particularly in acrocentric chromosomes, studied by the Hi-C technique. However, 3D-genome rearrangement, caused by NAT10 deficiency and UVC irradiation, did not significantly impact post-translational histone modifications. Overall, NAT10 depletion alters the pool of key DNA repair proteins and induces substantial 3D-genome reorganization.
