The Landscape of Histone Modifications in Epigenomics Since 2020

Histone proteins are a primary component of chromatin; therefore, any modifications to their structure are anticipated to affect the behavior of our genetic material, which is manifested in the form of phenotypic changes at a molecular, cellular or organic level. The majority of histone modifications are of either methylation or acetylation type that regulate gene expression. Though, not all of these modifications are concerned with the direct regulation of gene transcription. Throughout its 13-year run, Epigenomics has never ceased to cover these most gripping epigenetic stories, a significant proportion of which is in the matter of histones and their modifications. As such, the current perspective piece is intended to highlight original histone-oriented contributions published in Epigenomics since 2020.Histones are proteins and, as with any other protein, they are made of a series of amino acid molecules, a number of which, including arginine and lysine, can be modified by the addition or removal of already-existing methyl, acetyl or phosphate groups. This sort of modification most often results in altered gene expression, as the increased or decreased density of modifiers can negatively or positively affect the accessibility of genes to transcription factors. In essence, this is known as the epigenetic regulation of gene expression, since the genetic sequence stays intact while nongenetic protein molecules orchestrate a series of dynamic events that determine the function of the cell. For that reason, these modifications are highly important because, in contrast to genetic mutations, they do not immediately or profoundly become manifest in the phenotype, a characteristic that has rendered them subject to extensive investigations. Each year, a fair proportion of these studies are published in Epigenomics. As the editorial board, it is our duty to highlight them, every once in a while, for our readership. As research in the field of histone modifications is constantly evolving through the invention of new bioanalytical tools and the identification of novel modifications to the structure of the nucleosome, spotlighting pertinent research on a regular basis could be good practice for keeping us receptive to future perspectives regarding the matter.