histone deacetylase 4
The HDAC4 gene provides instructions for making an enzyme called histone deacetylase 4. This enzyme is part of a group of related enzymes, called histone deacetylases, that modify proteins called histones. Histones are structural proteins that attach (bind) to DNA and give chromosomes their shape.
By removing a molecule called an acetyl group from histones (a process called deacetylation), histone deacetylases cause the DNA within chromosomes to become tightly packed (compressed). As a result, proteins called transcription factors, which attach (bind) to specific regions of DNA and help control the activity of particular genes, cannot access the DNA. Through deacetylation of histones, histone deacetylase 4 is able to control (regulate) the activity of certain genes.
Histone deacetylase 4 appears to be particularly important for regulating the activity of genes involved in heart and skeletal development. This protein is also involved in nerve cell survival.
2q37 deletion syndrome is caused by deletions of genetic material near the end of the long (q) arm of chromosome 2, at a location designated 2q37. The signs and symptoms of 2q37 deletion syndrome vary widely, but affected individuals generally have intellectual disability, behavioral problems, obesity, and skeletal abnormalities that often include unusually short fingers and toes (brachydactyly).
The chromosomal region that is deleted in 2q37 deletion syndrome varies among affected individuals and can contain many genes, but it always includes the HDAC4 gene. As a result of the deletion, people with this condition have only one copy of the HDAC4 gene in each cell instead of the usual two copies. Researchers believe that deletion of the HDAC4 gene, and a reduction in the amount of histone deacetylase 4 produced, accounts for many of the features of 2q37 deletion syndrome. A shortage of histone deacetylase 4 enzyme likely disrupts the regulation of many genes and contributes to intellectual disability, behavioral problems, skeletal abnormalities, and other features of 2q37 deletion syndrome.
Some people with a mutation in only the HDAC4 gene have brachydactyly with no other health problems, while others have many features of 2q37 deletion syndrome. Researchers are studying why mutations in this gene can lead to a wide variety of signs and symptoms and what role the other genes on 2q37 play in the disorder.
- histone deacetylase A
- Biochemistry (fifth edition, 2002): Histone Deacetylases Contribute to Transcriptional Repression
- Madame Curie Bioscience Database: Histone Modifications Marking the Inactive Transcriptional State
- Molecular Cell Biology (fourth edition, 2000): Repressors Can Direct Histone Deacetylation at Specific Genes