Monoubiquitylation of histone H2B

Chromatin modifications play key roles in the regulation of gene expression. Cancer cells often display altered chromatin modification patterns, which may contribute to their cancerous features. Our lab is studying one such particular modification: monoubiquitylation of histone H2B (H2B-ub), which is primarily carried out by the E3 ubiquitin ligase RNF20. Many human cancer types display reduced levels of histone H2B-ub, particularly observed in more aggressive tumors. Earlier work from our lab demonstrated that downregulation of RNF20 and H2B-ub promotes a more cancerous behavior, both in culture and in vivo.  Thus, RNF20 has features of a tumor suppressor.
In our present work, we are attempting to understand how the levels of H2B-ub are regulated in normal and cancer cells, and how reduced levels of H2B-ub promote cancer.