Myelin Oligodendrocyte Glycoprotein (MOG) is one of the proteins in myelin, a fatty insulating substance found in the white matter of the central nervous system. Myelin wraps around axons, the long extensions of nerve cells (neurons). Myelin and myelin oligodendrocyte glycoprotein are produced by maintenance cells called oligodendrocytes.
MOG is confined to oligodendrocyte bodies and the outermost surface of the myelin sheath. The precise function of MOG is unknown but it is believed to be important in defining the structural integrity of the myelin sheath. Another myelin protein, proteolipid protein (PLP), that is found within the myelin sheath appears to act in a mutually exclusive way with MOG and both seem to be important in giving myelin its structure. It is also believed that MOG might act as an adhesive.
Some have also suggested that MOG might normally interact with proteins in the immune system particularly those that make up part of the innate immune system known as the complement.
MOG is believed to be one of principle targets of the immune system attack seen in multiple sclerosis (MS). MS is believed to be an autoimmune disease - a type of disease where the body's own immune system attacks itself. A branch of the immune system known as the acquired immune system target sections of proteins called antigens. In autoimmune diseases, antigens in the body's own proteins are targeted and these are called autoantigens.
MOG's role in providing potential autoantigens in MS is supported both by it's location at the cell surface and by immunological work done in both humans and animal models of multiple sclerosis (EAE). It is possible that MOG is one of several myelin proteins targeted in MS and some evidence suggests that the range of autoantigens attacked broadens as the disease progresses.
Oligodendroglial Cell Biology and CNS Myelination
Autoimmunity to MOG in Rats Mimics the Spectrum of MS Pathology
Autoimmunity to MOG: Relevance for human MS
The Structure & Function Of MOG
Elevated Levels of Antibody to MOG Is Not Specific for Patients With MS