Histone H3.3 phosphorylation amplifies stimulation-induced transcription

Area of Science:

• Molecular Biology
• Epigenetics
• Cellular Biology

Background:

• Gene induction in complex organisms relies on chromatin regulation.
• Histone variant H3.3 is enriched in dynamically regulated chromatin.
• Mechanisms enabling rapid, high-level transcription at induced genes remain unclear.

Purpose of the Study:

• To investigate the role of histone variant H3.3 in rapid gene induction.
• To identify specific features of H3.3 that facilitate transcription.
• To elucidate the molecular mechanisms underlying stimulation-responsive gene regulation.

Main Methods:

• Analysis of histone modifications in mouse macrophages.
• Mass spectrometry to identify interacting proteins.
• Chromatin immunoprecipitation to assess histone variant localization.

Main Results:

• Phosphorylation of H3.3 at Serine 31 (H3.3S31ph) occurs on rapidly induced genes.
• H3.3S31ph selectively engages histone methyltransferase SETD2.
• H3.3S31ph facilitates the ejection of elongation corepressor ZMYND11.

Conclusions:

• H3.3S31ph is a key mark for stimulation-responsive genes.
• This phosphorylation provides preferential access for the transcription apparatus.
• Dedicated mechanisms involving H3.3 phosphorylation regulate rapid transcription.