Neurofibrils

NF-L neurofilament, light or low polypeptide ~68kDa
Identifiers
Symbol	NEFL
Entrez	4747
HUGO	7739
OMIM	162280
RefSeq	NM_006158
UniProt	P07196
Other data
Locus	Chr. 8 p21

NF-M Neurofilament 3 145-160kDa medium or middle neurofilament subunit
Identifiers
Symbol	NEF3
Alt. symbols	NEFM
Entrez	4741
HUGO	7734
OMIM	162250
RefSeq	NM_005382
UniProt	P07197
Other data
Locus	Chr. 8 p21

NF-H 200-220kDa heavy or high molecular weight neurofilament subunit
Identifiers
Symbol	NEFH
Entrez	4744
HUGO	7737
OMIM	162230
RefSeq	NM_021076
UniProt	P12036
Other data
Locus	Chr. 22 q12.1-13.1

Alpha-internexin neuronal intermediate filament protein
Identifiers
Symbol	INA
Alt. symbols	NEF5
Entrez	9118
HUGO	6057
OMIM	605338
RefSeq	NM_032727
UniProt	Q5SYD2
Other data
Locus	Chr. 10 q24

Nestin intermediate filament subunit of neuronal stem cells
Identifiers
Symbol	NES
Entrez	10763
HUGO	7756
OMIM	600915
RefSeq	NP_006608
UniProt	P48681
Other data
Locus	Chr. 1 q23.1

Neurofilaments (NF) are the 10 nanometer or intermediate filaments found in neurons. They are a major component of the neuronal cytoskeleton, and are believed to function primarily to provide structural support for the axon and to regulate axon diameter. Neurofilaments are composed of polypeptide chains or subunits which belong to the same protein family as the intermediate filaments of other tissues such as keratin subunits, which make 10 nm filaments expressed specifically in epithelia. The family of proteins making intermediate filaments is divided into 5 major classes, the keratins forming the classes I and II. Class III contains the proteins vimentin, desmin, peripherin and glial fibrillary acidic protein (GFAP). The major neurofilament subunits occupy the class IV family of intermediate filaments, along with two other filament proteins of neurons, alpha-internexin and nestin. The class IV intermediate filament genes all share two unique introns not found in other intermediate filament gene sequences, suggesting a common evolutionary origin from one primitive class IV gene. Finally, class V corresponds to intermediate filaments of the nuclear cytoskeleton, the nuclear lamins. The term neurofibril refers to a bundle of neurofilaments.

The three major neurofilament subunits were discovered from studies of axonal transport. Proteins are synthesized within the cell body, and hence they must travel along the axon to reach their final destination. The names given to the three major neurofilament subunits are based upon the apparent molecular mass of the mammalian subunits on SDS-PAGE:

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Wikipedia