Anti-Glutamine Synthetase is produced in rabbit using a synthetic peptide corresponding to the C-terminus of mouse glutamine synthetase (GS) conjugated to keyhole limpet hemocyanin (KLH) as immunogen. This sequence is identical in human, bovine, rat, hamster and pig GS, and highly conserved in chicken GS. GS is found in mammals as an octamer of identical 45 kDa subunits. It is localized in glial cells of various species. It is present in the brain primarily in astrocytes and in the retina in Muller glial cells that support neurons using glutamate as a neurotransmitter. GS is found in several brain regions including hippocampus, cerebral cortex, neostriatum and cerebellar granular layer, corresponding to sites with high glutamate receptor density.
GLUL (glutamate-ammonia ligase) gene encodes an ATP-dependent enzyme that catalyzes the synthesis of glutamine from glutamate and ammonia (nitrogen source). It is a member of the glutamine synthetase family. It is an essential enzyme in glutamine neogenesis. It functions in detoxification of ammonia and glutamate, acid-base homeostasis, cell signaling, and cell proliferation. It has a role in proliferation of fetal skin fibroblasts. Defects in this gene are associated with congenital glutamine deficiency. Overexpression of this gene has been observed in some primary liver cancer samples.