Antigen/Purification: Collapse
The antigen is a recombinant rat alpha-internexin expressed in and purified from E. coli.
The antibody is total IgG fraction.
Biological Significance: Collapse
Alpha-internexin is a Class IV intermediate filament originally discovered as it co-purifies with other neurofilament subunits (1). Alpha-internexin 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 only in neurons and in large amounts early in neuronal development, but is down-regulated 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 alphainternexin 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, recent studies show a marked up-regulation of alpha-internexin during neuronal regeneration (2). 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. Recently Cairns et al. used this antibody to show that alphainternexin is an abundant component of the inclusions of neurofilament inclusion body disease (NFID), a serious human neurodegenerative disorder (3,4). The antibody was also used to confirm the presence of circulating auto-antibodies to alpha-internexin in the sera of some patients with endocrine autoimmunity, as well as in some normal individuals (5).
Storage
Liquid containing 10mM sodium azide.
For long term storage –20° C is recommended in undiluted aliquots. Stable at –20° C for at least 1 year. Avoid freeze/thaw cycles.
General References
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).
McGraw et al. Axonally transported peripheral signals regulate alpha-internexin expression in regenerating motoneurons. J Neurosci 22:4955-63 (2002).
Cairns NJ et al. alpha-Internexin aggregates are abundant in neuronal intermediate filament inclusion disease (NIFID) but rare in other neurodegenerative diseases. Acta Neuropathol (Berl). May 28 [Epub ahead of print] (2004).
Cairns NJ et al. alpha-internexin is present in the pathological inclusions of neuronal intermediate filament inclusion disease. Am J Pathol. 164:2153-61 (2004).
Rajasalu T, Teesalu K, Janmey PA, Uibo R. Demonstration of natural autoantibodies against the neurofilament protein alpha-internexin in sera of patients with endocrine autoimmunity and healthy individuals. Immunol Lett. 94:153-60 (2004).
