CDK9 directs H2B monoubiquitination and controls replication-dependent histone mRNA 3'-end processing
- EMBO Rep. 2009 Aug;10(8):894-900. doi: 10.1038/embor.2009.108.
- 1. Department of Molecular Oncology, Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany.
Post-translational histone modifications have essential roles in controlling nuclear processes; however, the specific mechanisms regulating these modifications and their combinatorial activities remain elusive. Cyclin-dependent kinase 9 (CDK9) regulates gene expression by phosphorylating transcriptional regulatory proteins, including the RNA polymerase II carboxy-terminal domain. Here, we show that CDK9 activity is essential for maintaining global and gene-associated levels of histone H2B monoubiquitination (H2Bub1). Furthermore, CDK9 activity and H2Bub1 help to maintain correct replication-dependent histone messenger RNA (mRNA) 3'-end processing. CDK9 knockdown consistently resulted in inefficient recognition of the correct mRNA 3'-end cleavage site and led to increased read-through of RNA polymerase II to an alternative downstream polyadenylation signal. Thus, CDK9 acts to integrate phosphorylation during transcription with chromatin modifications to control co-transcriptional histone mRNA processing.