Post-translational modifications of histones

Post-translational modification (PTM) of histones is a crucial step in epigenetic regulation of genes. N-terminal tails of histones are the most accessible regions as they protrude out from the nucleosome. These tails are subjected to various modifications such as acetylation, methylation, phosphorylation, ubiquitination etc. Histone PTMs are known to alter the total charge on histone proteins thereby affecting there interaction with DNA and altering nucleosome stability. Also, PTMs are known to either create sites for the recruitment or modify existing sites so as to abolish interactions with factors like ‘writer’, ‘eraser’ or ‘readers’ and thereby regulating gene expression.

Types of PTMs Arginine citrullination, Arginine methylation, Glutamine methylation, Lysine acetylation, Lysine biotinylation, Lysine methylation, Lysine ribosylation, Lysine sumoylation, Lysine ubiquitination, Serine/threonine/tyrosine phosphorylation