The impact of phosphorylated histone H3 on the reformation of nuclear envelope.

Abstract

Histones are known to play an integral role in the organization of genomic material in cells. Post-translation modifications (PTMs) of histones have therefore been the focus of much research over the years. Histone H3, in particular, has been identified as the main histone subjected to such PTMs. Phosphorylation of histone H3 on Serine-10 has been proposed to trigger the onset of mitosis in cells. In contrast, dephopshorylation of the stated residue prompts the cell to exit from mitosis, implying the significance of this PTM. Here, I try to determine the functional significance of histone H3 serine-10 dephosphorylation on nuclear envelope (NE) reassembly during mitotic exit. Immunostaining analysis has shown that these two events coincide during late mitosis, implying an existing temporal coordination. In order to gain a better understanding of this phenomenon, cells were subjected to transfection with mutant H3 plasmids as well as with small interfering RNA (siRNAs) targeted against histone H3. By doing so, I aimed to elucidate how phosphorylation status of histone H3 might affect the timing and reformation of NE