Figure 4.

m⁶A RNAs were present at only CPD-positive chromatin, and inhibitors of RNA pol I and RNA pol II did not affect the m⁶A RNA level in the microirradiated regions. (a) An inhibitor of RNA pol II, α-amanitin, did not affect m⁶A RNA levels at the DNA lesions. For an illustration of RNA pol II inhibition (red i), the RNA pol II elongation complex was adapted from the PDB database [51]. (b) Summary of the inhibitory effects (treatment by actinomycin D, A-196, and α-amanitin) on m⁶A RNA levels. Quantification was performed according to microirradiated ROIs. (c) Chromatin with (a’) γH2AX positivity in microirradiated ROI and (b’) with/without CPDs. Results are shown after exposure to the 355-nm laser or 405-nm laser line. (d) Panels show DNA lesions (absent of CPDs) induced by the 405-nm laser line. The 355-nm laser-induced both γH2AX and m⁶A RNAs in the microirradiated genome. (e) In comparison to (a’) nontreated cells and (b’) an inhibitor of H4K20me2/me3, A-196 did not affect the level of m⁶A RNAs in the microirradiated chromatin. A structure of the inhibitor of the SUV4-20h1/h2 methyltransferases, the compound A-196, was adopted from the PDB database (it is an example of H4K20me inhibition) [41]. (f) Nuclear distribution of m⁶A RNAs in a’ nonirradiated, b’ UVA irradiated, c’, and UVC irradiated MEFs (whole-cell cultures were irradiated). White frames show the level of m⁶A RNAs in the cytoplasm. The scale bar in panel (a) represent 8 µm; in panels c, a’, and b’ they represent 10 µm; in panels d,e 5 µm; in panels fa’,b’ bars are 5 µm; and in panels fc’ it is 10 µm in Suv39h1/h2 wt cells and 15 µm in Suv39h1/h2 dn cells.