PIGW

PIGW is a gene that encodes for the protein known as phosphatidylinositol glycan anchor biosynthesis class W. This protein is involved in the process of glycosylphosphatidylinositol (GPI) anchor biosynthesis. The GPI anchor is a glycolipid that can be attached to the C-terminus of a protein during posttranslational modification.

Function

The PIGW protein is a component of the GPI-N-acetylglucosaminyltransferase (GPI-GnT) complex. This complex catalyzes the transfer of N-acetylglucosamine (GlcNAc) from UDP-GlcNAc to phosphatidylinositol (PI), the first step in the production of GPI anchors. The PIGW protein specifically is believed to have acyltransferase activity, adding a fatty acid to the inositol ring of PI to form acyl-PI.

Clinical significance

Mutations in the PIGW gene have been associated with a number of diseases. For example, a homozygous mutation in PIGW has been identified in patients with West syndrome, a severe form of epilepsy that begins in infancy. This mutation results in a loss of PIGW function, leading to a decrease in the number of proteins that can be GPI-anchored and a corresponding increase in neuronal excitability.

See also

• Phosphatidylinositol-glycan biosynthesis
• Glycosylphosphatidylinositol anchor
• West syndrome

References

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