MAG (myelin associated glycoprotein) is a Adhesion molecule in postnatal neural development that mediates sialic-acid dependent cell-cell interactions between neuronal and myelinating cells. Preferentially binds to alpha2,3-linked sialic acid. Isoform L-MAG is critical for the formation of myelin in the CNS, whereas isoform S-MAG is sufficient to maintain the integrity of myelin in PNS. Binds to RTN4R. single-pass type I membrane protein. Expressed by myelinating glial cells in the central ａn