GSE137748
Genome wide chromatin profile for Histone H1.4 (pan-H1.4) and Phosphorylated H1.4 (pS187-H1.4)
In this study, we use novel, highly specific custom antibodies against a linker histone variant and its modified form to conduct chromatin immunoprecipitation (ChIP)  followed by Next Generation Sequencing (NGS)  to investigate their binding profiles as a result of transcription inititation. Here we use an estrogen responsive breast cancer cell line, MCF7 to study the enrichment patterns of Histone H1.4 (pan-H1.4) and Phosphorylated H1.4 (pS187-H1.4) across the genome as a result of a short estrogen treatment (30 mins). We find that pS187-H1.4 is preferentially enriched at the promoters of active genes as opposed to the depletion of pan-H1.4 at the same site. Additionally, we use a short treatment of Flavopiridol- an inhibitory drug specific for Cyclin-dependent Kinase-9 (CDK9) which is responsible for the phosphorylation of H1.4 cells, to demonstrate the quenching of this signal at sites specificially activated as a result of the estrogen treatment. This demonstrates for the first time that pS187-H1.4 is associated with active genes and may even be involved in the regulation of gene activity. Overall design: Examination of Histone H1.4 and pS187H1.4 marks across the genome to evaluate their response to transcription activation