Histone modification H3.3S31ph regulates chromatin dynamics and macrophage immune responses

A histone modification, H3.3S31ph, transforms nucleosomes from stable to dynamically activated states, offering new insights into epigenetic regulation. Researchers discovered that histone variant H3.3 enhances nucleosome integrity after disruption and recruits the FACT complex more efficiently. Phosphorylation at Ser31 reverses this stability, facilitating transcriptional activation. This mechanism is crucial in macrophage immune responses, enabling rapid transcriptional shifts. The findings suggest potential therapeutic applications for chromatin-related diseases.