Internexin Alpha/NF66 [2E3]

Alpha–internexin is an intermediate filament family member expressed during early neuron development and is related to the neurofilament proteins NF-H, NF-L and NF-M. Due to the specific spatial and temporal expression pattern of alpha-internexin, it is a useful marker of neuronal subtypes. It is related to but distinct from the better known neurofilament triplet proteins, NF-L, NF-M and NF-H, having similar protein sequence motifs and a similar intron organization. It is expressed in large amounts early in neuronal development, but is downregulated in many neurons as development proceeds. Many classes of mature neurons contain alpha-internexin in addition to NF-L, NF-M and NF-H. In some mature neurons alpha-internexin is the only neurofilament subunit expressed. Antibodies to a-internexin are therefore unique probes to study and classify neuronal types and follow their processes in sections and in tissue culture. The very early developmental expression of alpha-internexin means its presence is an early and convenient diagnostic feature of neuronal progenitors cells and other cell committed to the neuronal lineage. Recent studies show a marked up-regulation of a-internexin during neuronal regeneration.