TAF1

The TAF1 gene provides instructions for making part of a protein called transcription factor IID (TFIID). This protein is active in cells and tissues throughout the body, where it attaches (binds) to DNA. Transcription factor IID plays an essential role in regulating the activity of most genes.

The TAF1 gene is part of a complex region of DNA known as the TAF1/DYT3 multiple transcript system. This region consists of short stretches of DNA from the TAF1 gene plus some extra segments of genetic material near the gene. These stretches of DNA can be combined in different ways to create various sets of instructions for making proteins. Researchers believe that some of these variations are critical for the normal function of nerve cells (neurons) in the brain.

X-linked dystonia-parkinsonism - caused by mutations in the TAF1 gene

Several changes in the TAF1/DYT3 multiple transcript system have been identified in people with X-linked dystonia-parkinsonism. Some alter single DNA building blocks (nucleotides) in the gene; these changes are described as disease-specific single-nucleotide changes (DSCs). Another genetic change deletes a small number of nucleotides from the gene. Researchers are uncertain how these changes are related to the movement abnormalities characteristic of the disease.

X-linked dystonia-parkinsonism may also be related to an extra segment of DNA in the TAF1/DYT3 multiple transcript system. The extra segment results from the insertion of a retrotransposon, which is a small piece of DNA that can move around to different positions in a cell's genetic material. When a retrotransposon inserts itself in or a near a gene, it can disrupt the gene's function. In this case, the retrotransposon insertion probably interferes with the normal function of the TAF1/DYT3 multiple transcript system.

Researchers suspect that changes in the TAF1/DYT3 multiple transcript system disrupt the regulation of critical genes in neurons. This defect leads to the eventual death of these cells, particularly in areas of the brain called the caudate nucleus and putamen. These regions are critical for normal movement, learning, and memory. It is unclear why the effects of changes in the TAF1/DYT3 multiple transcript system appear to be limited to dystonia and parkinsonism.