Fig. 7. H3K4 methylation defends the genome from TRCs-mediated instability under replication stress.
a HU sensitivity was determined for WT and isogeneic set1Δ, bre2Δ, and spp1Δ strains, as well as the H3 strain and isogeneic H3K4A, H3R2A, H3K36A and H3K79A mutants. b Putative elevated H3K4me and c actual H3K4me3 after pTEF promoter was introduced into the CAN1 gene; error bars represent ± SEM (n = 3 technical replicates). Mutation rates of d native CAN1 (left panel) and pTEF-CAN1 (right panel) were measured by the fluctuation test (see Methods section) in RAD53-H3, RAD53-H3K4A, rad53-H3 and rad53-H3K4A cells. rad53 refers to rad53-K227A mutant. As in d, cells were treated by e 5 mM and f 100 mM HU. Data are the median with 95% confidence intervals (n = 11 independent samples). Statistical significance was determined by Mann–Whitney U-test; p < 0.05; asterisks represent p < 0.001 compared with RAD53-H3 or RAD53-H3K4A; ND, not determined.