A role for Mog1 in H2Bub1 and H3K4me3 regulation affecting RNAPII transcription and mRNA export.

Paula Oliete‐Calvo,Bernhard Dichtl,Luis M Soares,Joan Serrano‐Quílez,José E Pérez‐Ortín,María E Pérez‐Martínez,Stephen Buratowski,Susana Rodríguez‐Navarro,Carme Nuño‐Cabanes

doi:10.15252/embr.201845992

Abstract

Monoubiquitination of histone H2B (to H2Bub1) is required for downstream events including histone H3 methylation, transcription, and mRNA export. The mechanisms and players regulating these events have not yet been completely delineated. Here, we show that the conserved Ran-binding protein Mog1 is required to sustain normal levels of H2Bub1 and H3K4me3 in Saccharomyces cerevisiae Mog1 is needed for gene body recruitment of Rad6, Bre1, and Rtf1 that are involved in H2B ubiquitination and genetically interacts with these factors. We provide evidence that the absence of MOG1 impacts on cellular processes such as transcription, DNA replication, and mRNA export, which are linked to H2Bub1. Importantly, the mRNA export defect in mog1Δ strains is exacerbated by the absence of factors that decrease H2Bub1 levels. Consistent with a role in sustaining H2Bub and H3K4me3 levels, Mog1 co-precipitates with components that participate in these modifications such as Bre1, Rtf1, and the COMPASS-associated factors Shg1 and Sdc1. These results reveal a novel role for Mog1 in H2B ubiquitination, transcription, and mRNA biogenesis.

Highlights

Eukaryotic gene expression is a complex process that is regulated at multiple levels, including nuclear and cytoplasmic events
These results reveal a novel role for Mog1 in H2B ubiquitination, transcription and mRNA biogenesis
It has been shown that deletion of either deubiquitination module (DUBm) subunits Sgf11 or Sgf73 exacerbates mRNA export defects [35,36], while the TREX-2 subunit Sem1 is required for SAGAdependent deubiquitinating activity [37]

Summary

Introduction

Eukaryotic gene expression is a complex process that is regulated at multiple levels, including nuclear and cytoplasmic events. Consistent with a role in sustaining H2Bub and H3K4me3 levels, Mog1 co-precipitates with components that participate in these modifications such as Bre1, Rtf1, and the COMPASS associated factors Shg1 and Sdc1. We demonstrate that deletion of MOG1 affects the global levels of both H2Bub1 and H3K4me3 and the chromatin recruitment of factors implicated in their modifications.

Results

Conclusion