The Aurora B Kinase and the Polycomb Protein Ring1B Combine to Regulate Active Promoters in Quiescent Lymphocytes

•Aurora B and Ring1B co-occupy active promoters in resting lymphocytes•Loss of Ring1B or Aurora B reduces transcription and binding of RNAPII•Aurora B enhances binding of USP16 and phosphorylates histone H3S28•Ubiquitination of H2A by Ring1B is inhibited by phosphorylation of UBE2D3

SummaryReversible cellular quiescence is critical for developmental processes in metazoan organisms and is characterized by a reduction in cell size and transcriptional activity. We show that the Aurora B kinase and the polycomb protein Ring1B have essential roles in regulating transcriptionally active genes in quiescent lymphocytes. Ring1B and Aurora B bind to a wide range of active promoters in resting B and T cells. Conditional knockout of either protein results in reduced transcription and binding of RNA Pol II to promoter regions and decreased cell viability. Aurora B phosphorylates histone H3S28 at active promoters in resting B cells as well as inhibiting Ring1B-mediated ubiquitination of histone H2A and enhancing binding and activity of the USP16 deubiquitinase at transcribed genes. Our results identify a mechanism for regulating transcription in quiescent cells that has implications for epigenetic regulation of the choice between proliferation and quiescence.

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