From the Research
Alpha internexin is a crucial neuronal intermediate filament protein that plays a significant role in the development and maintenance of neuronal structure, particularly in axons, and its expression is closely associated with neurofilament proteins in the central nervous system. This protein is primarily expressed in the central nervous system and is involved in the formation of homopolymers or heteropolymers with other intermediate filament proteins like neurofilament light, medium, and heavy chains to provide structural support and regulate axon diameter 1. The expression of alpha internexin is an important marker for neuronal differentiation in developmental studies and can help identify specific neuronal populations in research contexts.
Some key points about alpha internexin include:
- It is a type IV intermediate filament protein that is structurally and functionally associated with the neurofilament triplet proteins in the mature CNS 2.
- Alpha internexin is expressed early during neuronal development, preceding other neurofilament proteins, and helps establish the neuronal cytoskeleton 3, 4.
- It is also used as a marker for neuronal differentiation in developmental studies and can help identify specific neuronal populations in research contexts.
- Abnormal accumulation of alpha internexin has been associated with certain neurodegenerative disorders, particularly neuronal intermediate filament inclusion disease (NIFID), where it forms pathological inclusions in neurons.
In terms of its relationship with other neurofilament proteins, alpha internexin is functionally interdependent with the neurofilament proteins and is considered a fourth subunit of neurofilaments in the adult CNS 2. This interdependence is crucial for maintaining axonal stability and transport, and any disruption in this relationship can lead to neurodegenerative disorders. Overall, alpha internexin plays a vital role in the development and maintenance of neuronal structure and function, and its expression is closely tied to the expression of other neurofilament proteins in the central nervous system.