General Description
Glial fibrillary acidic protein (GFAP) is a member of the class III intermediate filament protein family. It is heavily, and specifically, expressed in astrocytes and certain other astroglia in the central nervous system, in satellite cells in peripheral ganglia, and in non myelinating Schwann cells in peripheral nerves. In addition, neural stem cells frequently strongly express GFAP. Antibodies to GFAP are therefore very useful as markers of astrocytic cells. In addition, many types of brain tumors presumably derived from astrocytic cells, heavily express GFAP. GFAP is also found in the lens epithelium, Kupffer cells of the liver, in some cells in salivary tumors and has been reported in erythrocytes. GFAP is particular expressed in auricular chondrocytes.
Biochem/physiol Actions
Glial fibrillary acidic protein (GFAP) maintains the structure and motility of astrocytes. Gfap mediates the interaction between neurons and glial cells. It is responsible for the integrity and function of blood-brain barrier. Myelination and brain injury induced astrogliosis is controlled by Gfap. Cytoskeleton disintegration is known to stimulate the release of Gfap. Upregulation of this gene is observed in traumatic brain injury such as intracerebral hemorrhage and thus serves as a biomarker. Mutation in the GFAP gene causes Alexander disease.
