Regulation of the SUV39H Family Methyltransferases: Insights from Fission Yeast

Histones, which make up nucleosomes, undergo various post-translational modifications, such as acetylation, methylation, phosphorylation, and ubiquitylation. In particular, histone methylation serves different cellular functions depending on the location of the amino acid residue undergoing modification, and is tightly regulated by the antagonistic action of histone methyltransferases and demethylases. The SUV39H family of histone methyltransferases (HMTases) are evolutionarily conserved from fission yeast to humans and play an important role in the formation of higher-order chromatin structures called heterochromatin. The SUV39H family HMTases catalyzes the methylation of histone H3 lysine 9 (H3K9), and this modification serves as a binding site for heterochromatin protein 1 (HP1) to form a higher-order chromatin structure. While the regulatory mechanism of this family of enzymes has been extensively studied in various model organisms, Clr4, a fission yeast homologue, has made an important contribution. In this review, we focus on the regulatory mechanisms of the SUV39H family of proteins, in particular, the molecular mechanisms revealed by the studies of the fission yeast Clr4, and discuss their generality in comparison to other HMTases.

Automated summary

Histones, the building blocks of nucleosomes, undergo various post-translational modifications, including methylation. The SUV39H family of histone methyltransferases is evolutionarily conserved and plays a crucial role in forming higher-order chromatin structures. By catalyzing the methylation of histone H3 lysine 9, they create a binding site for heterochromatin protein 1, which contributes to the formation of heterochromatin. Studies on the fission yeast Clr4 have provided important insights into the regulatory mechanisms of this enzyme family, which can be compared to other histone methyltransferases.