High molecular weight tau: preferential localization in the peripheral nervous system.

Using epitope mapping we have demonstrated that a high molecular weight protein (Mr approximately 115 x 10(3)) present in brain and spinal cord is a member of the tau family of microtubule-associated proteins. Antibodies directed against the amino-terminal, middle and carboxyl-terminal portions of tau recognize this protein. A limited survey of neuronal tissues has shown that this high molecular weight tau protein is present in brain, spinal cord, dorsal root ganglia, dorsal and ventral roots and peripheral nerves. High molecular weight tau protein is expressed at higher levels in spinal cord than in brain and is the only form of tau detected in the adult peripheral nervous system.