| Popis: |
As an important histone modification, mono-ubiquitination of H2B (uH2B) widely regulates a series of events, including DNA replication, gene expression and transcription, DNA repair and heterochromatin maintenance. In Schizosaccharomyces pombe , uH2B occurs at its C-terminal lysine 119 dependent on Rhp6/Bre1 complex. Research shows that uH2B activates gene expression and regulates DNA repair via stimulating methylation of H3K4 and promoting mRNA elongation through destroying H2A/H2B dimer. We demonstrate that localization of Rhp6 silences spd1 by stimulating mono-ubiquitination of H2B at spd1 region and promoting dNTP synthesis to regulate DNA replication and DNA repair. Importantly, it depends on trimethylation of H3K9 instead of H3H4. Besides, enrichment of uH2B at double strand break site plays an important role in DNA repair through regulating chromatin structure, but the mechanism remains unclear. |
