PGAP2 gene
The PGAP2 gene provides instructions for a protein that modifies GPI anchors, which are essential for attaching specific proteins to the cell membrane.
Normal Function
The PGAP2 gene provides instructions for making a protein that modifies a molecule called a glycosylphosphosphatidylinositol (GPI) anchor. The GPI anchor attaches to various proteins and then binds them to the outer surface of the cell membrane, ensuring that they are available when needed.
The GPI anchor is assembled in the endoplasmic reticulum and then transferred to the Golgi apparatus. In the Golgi apparatus, the PGAP2 protein assists in attaching a molecule called a saturated fatty acid to the anchor. This saturated fatty acid is likely needed to help transport and attach the anchor to the fat-rich cell membrane.
Health Conditions Related to Genetic Changes
Mabry syndrome
At least five PGAP2 gene mutations have been found to cause Mabry syndrome. These mutations change single protein building blocks (amino acids) in the PGAP2 protein and likely reduce its activity. As a result, the PGAP2 protein cannot efficiently modify the GPI anchor, impairing the anchor's ability to attach itself and its associated protein to the cell membrane.
Features of Mabry syndrome include:
- Intellectual disability
- Distinctive facial features
- Hyperphosphatasia (increased levels of the enzyme alkaline phosphatase in the blood)
An enzyme called alkaline phosphatase is normally attached to the cell membrane by a GPI anchor. When the anchor is impaired, alkaline phosphatase is released from the cell, which is responsible for the hyperphosphatasia seen in this syndrome.
Other Names for This Gene
- cell wall biogenesis 43 N-terminal homolog
- CWH43-N
- FGF receptor activating protein 1
- FGF receptor-activating protein 1
- FRAG1
- PGAP2_HUMAN
- post-GPI attachment to proteins factor 2
