Neurofilament medium polypeptide

Neurofilament medium polypeptide (NF-M), encoded by NEFM, is an intermediate filament protein that forms the structural backbone of neuronal cytoskeletons (UniProt: P07197). It assembles with light and heavy neurofilament chains to maintain neuronal caliber and morphology, essential for proper axonal function and neuronal integrity.

NF-M is expressed throughout the nervous system as a key component of the neuronal cytoskeleton. UniProt records no primary disease association for this protein, though neurofilament dysfunction has been implicated in various neurological conditions affecting axonal integrity.

In Alzheimer's disease, NF-M shows significant downregulation in post-mortem brain tissue compared to age-matched controls (Chaparral AD proteomics), with a mean log2 fold-change of −0.221. This reduction may reflect neuronal loss or compromise of structural integrity characteristic of AD pathology, making NF-M a potential biomarker of neurodegeneration in the disease.