Chromatin-modifying enzymes gene family

Genes in this family provide instructions for making a group of proteins called chromatin-modifying enzymes. As their name suggests, these enzymes modify chromatin, a complex of DNA and proteins located in the nucleus of each cell. Chromatin is made up of DNA molecules wound tightly around proteins called histones. These proteins help organize the DNA and package it into larger thread-like structures called chromosomes. Chromatin-modifying enzymes alter histones by adding or removing certain small molecules. These changes regulate chromatin structure and influence gene transcription, which is the first step in the production of proteins from genes. Histone modification also influences the repair of damaged DNA and the copying (replication) of DNA molecules.

This family includes three types of chromatin-modifying enzymes: K-acetyltransferases or KATs (also known as histone acetyltransferases); K-methyltransferases or KMTs (also known as histone lysine methyltransferases); and K-demethylases or KDMs (also known as histone lysine demethylases). There are many ways to modify histones; the enzymes in this family each add or remove a specific molecule. K-acetyltransferases add small molecules called acetyl groups. K-methyltransferases add molecules called methyl groups, while K-demethylases remove methyl groups.

Because histone modification influences the transcription of many genes, this process is critical for many aspects of health and development. Mutations in genes in the chromatin-modifying enzyme family result in a wide variety of disorders characterized by intellectual disability, birth defects, and other developmental problems. Somatic (non-inherited) mutations in these genes have also been associated with the development of various types of cancer and non-cancerous tumors.