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

Area of Science:

• Neuroscience
• Cell Biology
• Protein Biochemistry

Background:

• Tau proteins are key microtubule-associated proteins crucial for neuronal function.
• The existence and distribution of high molecular weight tau isoforms in various neuronal tissues remain incompletely understood.

Purpose of the Study:

• To characterize a high molecular weight protein found in the brain and spinal cord.
• To determine if this protein belongs to the tau family of microtubule-associated proteins.
• To investigate the distribution of this high molecular weight tau protein across different neuronal tissues.

Main Methods:

• Epitope mapping using antibodies targeting different regions of tau.
• Western blot analysis to assess protein presence and molecular weight.
• Survey of various neuronal tissues including brain, spinal cord, and peripheral nerves.

Main Results:

• A high molecular weight protein (approximately 115 kDa) in the brain and spinal cord was identified as a member of the tau protein family.
• Antibodies against tau's amino-terminal, middle, and carboxyl-terminal regions recognized this protein.
• This high molecular weight tau protein is present in the brain, spinal cord, dorsal root ganglia, dorsal and ventral roots, and peripheral nerves.
• Higher levels of high molecular weight tau protein were observed in the spinal cord compared to the brain.
• It represents the sole tau protein detected in the adult peripheral nervous system.

Conclusions:

• The high molecular weight tau protein is a distinct member of the tau family.
• Its expression is widespread in the central and peripheral nervous systems.
• The spinal cord and peripheral nervous system show significant expression of this tau isoform.