Linker Histone H1.2 Cooperates with Cul4A and PAF1 to Drive H4K31 Ubiquitylation-Mediated Transactivation

Yue Xiong, Jaehoon Kim, Robert G. Roeder, Kyunghwan Kim, Jin Man Kim, Bomi Lee, Jongkyu Choi, Woojin An
Increasing evidence suggests that linker histone H1 can influence distinct cellular processes by acting as a gene-specific regulator. However, the mechanistic basis underlying such H1 specificity and whether H1 acts in concert with other chromatin-altering activities remain unclear. Here, we show that one of the H1 subtypes, H1.2, stably interacts with Cul4A E3 ubiquitin ligase and PAF1 elongation complexes, and that such interaction potentiates target gene transcription via induction of
more » ... iquitylation, H3K4me3 and H3K79me2. H1.2, Cul4A and PAF1 are functionally cooperative, as their individual knockdown results in the loss of the corresponding histone marks and the deficiency of target gene transcription. H1.2 interacts with the serine 2 phosphorylated form of RNAPII and we argue that it recruits the Cul4A and PAF1 complexes to target genes by bridging the interaction between the and the Cul4A and PAF1 complexes. These data define an expanded role for H1 in regulating gene transcription and illustrate its dependence on the elongation competence of RNAPII.
doi:10.17615/ynt0-8y58 fatcat:5e72vs2aazdfdb7vjxf5avf52i