Histone H3 Lysine 4 Mono-methylation does not Require Ubiquitination of Histone H2B (original) (raw)

2005, Journal of Molecular Biology

The yeast Set1-complex catalyzes histone H3 lysine 4 (H3K4) methylation. Using N-terminal Edman sequencing, we determined that 50% of H3K4 is methylated and consists of roughly equal amounts of mono, di and trimethylated H3K4. We further show that loss of either Paf1 of the Paf1 elongation complex, or ubiquitination of histone H2B, has only a modest effect on bulk histone mono-methylation at H3K4. Despite the fact that Set1 recruitment decreases in paf1D cells, loss of Paf1 results in an increase of H3K4 mono-methylation at the 5 0 coding region of active genes, suggesting a Paf1-independent targeting of Set1. In contrast to Paf1 inactivation, deleting RTF1 affects H3K4 mono-methylation at the 3 0 coding region of active genes and results in a decrease of global H3K4 mono-methylation.