Oligodendrocytic myelin paranodal and inner loop protein (OPALIN)

Oligodendrocytic myelin paranodal and inner loop protein (OPALIN) is a CNS-specific myelin membrane protein located predominantly in the paranodal loops of myelinated axons, and is essential for the regulation of oligodendrocyte differentiation and myelination in the central nervous system. OPALIN acts as a cell surface receptor for the neuronal protein LGI1, facilitating the differentiation of oligodendrocytes through the regulation of Sox10 and Olig2 transcription factors. Disruption of OPALIN, either genetically or functionally, leads to hypomyelination and white matter abnormalities—mirroring the effects seen in LGI1 deficiency. Structurally, it is a type I transmembrane protein with an extracellular N-terminal domain, a single transmembrane segment, and an extended intracellular C-terminal region, with proper glycosylation being necessary for its function and localization. OPALIN has been proposed as a potential target for promoting remyelination and is expressed in remyelinating plaques in disorders like multiple sclerosis. No direct drug interactions are known, but manipulation of the LGI1–OPALIN pathway is under consideration as a therapeutic strategy for demyelinating conditions.

Other names

OPALINOpalinHTMP10TMEM10TMP10transmembrane protein 10transmembrane protein TMP10

Acts as a receptor for leucine-rich glioma-inactivated protein 1 (LGI1); binding of LGI1 to OPALIN is essential for promoting oligodendrocyte differentiation and proper myelination