GPI : glucose-6-phosphate isomerase
Description
The GPI (glucose-6-phosphate isomerase) is a protein-coding gene located on chromosome 19.
The GPI gene provides instructions for making an enzyme called glucose phosphate isomerase (GPI). This enzyme has two distinct functions based on its structure. When two GPI molecules form a complex (a homodimer), the enzyme plays a role in a critical energy-producing process known as glycolysis, also called the glycolytic pathway. During glycolysis, the simple sugar glucose is broken down to produce energy. Specifically, GPI is involved in the second step of the glycolytic pathway; in this step, a molecule called glucose-6-phosphate is converted to another molecule called fructose-6-phosphate. When GPI remains a single molecule (a monomer) it is involved in the development and maintenance of nerve cells (neurons). In this context, it is often known as neuroleukin (NLK). The monomer is also produced by cancer cells and functions to promote spreading (metastasis) of the cancer; in this context it is called autocrine motility factor (AMF).
The GPI gene encodes the glucose phosphate isomerase (GPI) enzyme, which plays a crucial role in the second step of glycolysis, converting glucose-6-phosphate to fructose-6-phosphate. This enzyme is also involved in the reverse reaction during gluconeogenesis. Additionally, GPI acts as a secreted cytokine, functioning as an angiogenic factor (AMF) that stimulates endothelial cell motility. It also serves as a neurotrophic factor, known as neuroleukin, for spinal and sensory neurons. GPI is secreted by lectin-stimulated T-cells and induces immunoglobulin secretion.
GPI is also known as AMF, GNPI, NLK, PGI, PHI, SA-36, SA36.
Associated Diseases
- Hemolytic anemia, nonspherocytic, due to glucose phosphate isomerasedeficiency
- Glucose phosphate isomerase deficiency
