Post-translational Modifications of Newly Synthesized Histones H3 and the Role of H3 K56 Acetylation on Chromatin Assembly in Mammalian Cells

Abstract

The project I am presenting aimed to: 1. Elucidate the pattern of post- translational modification on the different variants of newly synthesized histones H3 in mammalian cells; 2. Reveal whether the acetylation of residue K56 on newly synthesized H3 histones plays a role in the incorporation of the histone into chromatin in mammalian cells; and 3. Determine whether the acetylation of residue K56 on newly synthesized H3 histones plays a role in the incorporation of the histone specifically in replicating chromatin in mammalian cells. The experiments to answer these questions were performed using HEK293 cells with inducible expression of FLAG-histones, enabling us to control the synthesis of new histones of interest and to detect and analyze their presence and relative levels in the cells. The results suggest that the acetylation of lysine 56 on histone H3 may play a positive role in the incorporation of the histone into new chromatin, and lack of acetylation may be reducing the efficiency of incorporation compared to acetylated histones.