Fig. 3

HBO1 involvement in DNA repair after UV irradiation. HBO1 plays a crucial role in the DNA repair process after UV irradiation, primarily associated with global genome nucleotide excision repair (GG-NER). Following UV-induced DNA damage, DDB2 recognizes the cyclobutyl pyrimidine dimer (CPD) site, and phosphorylated HBO1 binds to DDB2, mediating histone acetylation. HBO1 also maintains the chromatin remodeling agent ACF1–SNF2H at the damage site, inducing chromatin remodeling. Additionally, the methyltransferase MLL1 interacts with HBO1 and localizes at the UV damage site to methylate histone H3K4. BAZ1A, a subunit of the SWI/SNF chromatin remodeling factor, targets trimethylated histone H3K4 (H3K4me3). These mechanisms collectively disrupt the interaction between DNA and histones, facilitating the loading of NER factors including XPC for DNA repair