Technical Data
Internexin, alpha (alpha-Internexin, alpha-Inx, Ina, Inexa, Neurofilament-66, NF66)
Neurofilaments can be defined as the intermediate or 10nm diameter filaments found in neuronal cells. They are composed a mixture of subunits which often includes the neurofilament triplet proteins, NF-L, NF-M and NF-H. Neurofilaments may also include peripherin, alpha-internexin, nestin and in some cases vimentin. a-internexin is a ~66kD Class IV intermediate filament originally discovered as it copurifies with other neurofilament subunits (1). 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 procedes. 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 alpha-internexin are therefore unique probes to study and classify neuronal types and follow their processes in sections and in tissue culture. In addition 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. In addition recent studies show a marked up-regulation of alpha-internexin during neuronal regeneration (2), and that alpha-internexin positive inclusions are the hallmark of a type of frontotemporal dementia known as neurofilament inclusion body disease (3). The use of antibodies to this protein in the study of brain tumors has not been examined to date, but is likely to be of interest. The HGNC name for this protein is INA.

Suitable for use in Immunofluorescence and Western Blot. Other applications not tested.

Recommended Dilution:
Immunofluorescence: 1:1000
Western Blot: 1:10,000; On Western Blots use a brain or spinal cord homogenate and look for a major band at SDS-PAGE apparent molecular weight of 66 to 68kD. The human protein runs at ~68kD, while rat, mouse and other species run at ~66kD. Minor bands at ~150kD are probably covalent dimers, and bands at ~50kD represent a-internexin breakdown products.
Optimal dilutions to be determined by the researcher.

Storage and Stability:
May be stored at 4C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20C. Aliquots are stable for 12 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
100ul-20CBlue IceRatChicken
Not determined
Full length cDNA encoding rat alpha-internexin
Supplied as a liquid.
Recognizes rat a-Internexin.
Intended for research use only. Not for use in human, therapeutic, or diagnostic applications.
1. Pachter J and Liem RKH. Alpha-Internexin, a 66-kD intermediate filament-binding protein from mammalian central nervous tissues. J Cell Biol 101:1316-22 (1985).

2. McGraw T. et al. Axonally transported peripheral signals regulate alpha-internexin expression in regenerating motoneurons. J Neurosci 22:4955-63 (2002).

3. Josephs KA et al. Neurofilament inclusion body disease: a new proteinopathy? Brain 126:2291-2303 (2003).

4. Evans J et al. Characterization of mitotic neurons derived from adult rat hypothalamus and brain stem. J. Neurophysiol. 87:1076-85 (2002).