Myelin oligodendrocyte glycoprotein (MOG) is a member of the immunoglobulin (Ig) protein superfamily and is expressed exclusively in the central nervous system on the surface of myelin sheaths and oligodendrocyte processes. MOG is expressed at the onset of myelination, and therefore is a potential marker for oligodendrocyte maturation.
MOG contains an extracellular domain, a transmembrane domain, a cytoplasmic loop, a membrane-associated region and a cytoplasmic tail. MOG may function as a cell surface receptor or cell adhesion molecule. Fifteen different alternatively spliced isoforms have been detected in humans. These are present either on the cell surface, the endoplasmic reticulum in the endocytic system, or in secreted form.
The secreted form of MOG may trigger autoimmunity if released into the cerebrospinal fluid and periphery. MOG is thought to be a key target for autoantibodies and cell-mediated immune responses in inflammatory demyelinating diseases such as multiple sclerosis (MS) and is therefore widely studied in this field.
The MOG (35-55) fragment is the most potent auto-antigenic region of MOG, and the most effective at inducing experimental autoimmune/allergic encephalomyelitis (EAE), an animal model that resembles MS. This peptide has a free carboxylic acid at the C-terminus