Our laboratory focuses on understanding how newly synthesized histones are processed prior to their nuclear import and incorporation into chromatin. We and others have characterized a cytosolic maturation pathway through which histones acquire their proper folding and undergo specific post-translational modifications. This pathway involves several protein complexes, each defined by distinct histone chaperones and cofactors. Over recent years, we have investigated individual steps in this pathway and the cellular consequences of its dysregulation. More recently, our work has uncovered a previously unrecognized mechanism linking histone modifications and translation: lysine monomethylation and PARP1-mediated ADP-ribosylation cooperate to release histones H3 and H4 from ribosomes immediately after synthesis. These findings redefine the ribosome as an active platform for co-translational histone maturation, beyond its traditional role in protein synthesis.
We also study histone dynamics in the context of Hepatitis B virus (HBV) infection. We have found that histone modifications play a key role in regulating viral gene expression, and that the HBV regulatory protein HBx functions as an epigenetic modulator of the viral transcriptional program.