UBE3A

Ubiquitin-protein ligase E3A (UBE3A) also known as E6AP ubiquitin-protein ligase (E6AP) is an is_associated_with::enzyme that in humans is encoded by the UBE3A is_associated_with::gene. This enzyme is involved in targeting is_associated_with::proteins for degradation within cells.

Protein degradation is a normal process that removes damaged or unnecessary proteins and helps maintain the normal functions of cells. Ubiquitin protein ligase E3A attaches a small marker protein called is_associated_with::ubiquitin to proteins that should be degraded. Cellular structures called is_associated_with::proteasomes recognize and digest proteins tagged with ubiquitin.

Both copies of the UBE3A gene are active in most of the body's tissues. In the is_associated_with::brain, however, only the copy inherited from a person's mother (the maternal copy) is normally active; this is known as paternal imprinting. The UBE3A gene is located on the long (q) arm of is_associated_with::chromosome 15 between positions 11 and 13, from is_associated_with::base pair 23,133,488 to base pair 23,235,220.

Clinical significance
is_associated_with::Mutations within the UBE3A gene are responsible for some cases of is_associated_with::Angelman syndrome. Most of these mutations result in an abnormally short, nonfunctional version of ubiquitin protein ligase E3A. Because the copy of the gene inherited from a person's father (the paternal copy) is normally inactive in the brain, a mutation in the remaining maternal copy prevents any of the enzyme from being produced in the brain. This loss of enzyme function likely causes the characteristic features of these two conditions.

The UBE3A gene lies within the human chromosomal region 15q11-13. Other abnormalities in this region of chromosome 15 can also cause Angelman syndrome. These chromosomal changes include deletions, rearrangements (translocations) of genetic material, and other abnormalities. Like mutations within the gene, these chromosomal changes prevent any functional ubiquitin protein ligase E3A from being produced in the brain.

Interactions
UBE3A has been shown to interact with:


 * BLK,
 * is_associated_with::Lck,
 * is_associated_with::MCM7,
 * is_associated_with::MECP2,
 * is_associated_with::Progesterone receptor,
 * is_associated_with::TSC2,
 * is_associated_with::UBE2D1,
 * is_associated_with::UBE2D2,
 * is_associated_with::UBE2L3,
 * is_associated_with::UBQLN1, and
 * is_associated_with::UBQLN2.