Histone Methyltransferase Signaling Pathway

1. Histone Methyltransferase Signaling Pathway DNA and histones (H2A, H2B, H3, H4, H1) and some other proteins are combined and repeatedly folded and entangled to form a concentrated chromosome. Epigenetic modifications usually include DNA methylation and histone modification and RNA modification, while histone modifications phosphorylation, methylation, and ubiquitination. Most of the modifications are located at the N-terminus of histones. These modifications can affect the affinity of histones to DNA and change the state of chromatin. It can also affect the binding of transcription factors to DNA sequences and has a DNA-like genetic code for the regulation of gene expression, so it is called "histone code". Histone methylation refers to the occurrence of N-terminal arginine or lysine in H3 and H4 histones. Methylation at the residue of the amino acid is mediated by histone methyltransferase. The function of histone methylation is mainly reflected in heterochromatin formation, gene imprinting, and X chromosome inactivation and in terms of transcriptional regulation, 24 histone methylation sites are currently found, of which 17 are in lysine and the other 7 are in arginine. Lysine may be monomethylated, dimethylated, and trimethylated. include histone acetylation, Histone methyltransferase family The Su(var) 3-9 protein is the first histone lysine methyltransferase found in Drosophila, with a conserved SET domain-containing approximately 110 amino acids and being a plant ribulose diphosphate. Enzymes like Su(var)3-9 in mammals are SUV39H1 and SUV39H2, and in yeast Su(var) 3 -9 is like Clr4. These four enzymes only catalyze H3K9 methylation, while another methyltransferase G9a in mammals can not only catalyze H3K9 methylation but also catalyze H3K27 methylation. To found more methyltransferases, structural analysis methods are used to compare the currently known protein structures, and it is found that SET domain-associated proteins can be divided into four families, SET1, SET2, SUV39, and RIZ. Find more at: https://www.creative-diagnostics.com/histone-methyltransferase-signaling-pathway. htm