ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Abstract: Exposure of each of the three neurofilament proteins (NFPs) to AlCl3 resulted in their failure to migrate into sodium dodecyl sulfate (SDS)-containing gels. This effect was dependent on length of incubation (minimum, 2 h) and AlCl3 concentrations (minimum, 50 μM) and was not reversed by 20% SDS, 6 M urea, freeze-thawing, boiling, or extensive dialysis. The migration of vimentin and glial fibrillary acidic protein was not affected by AlCl3. The high-molecular-weight neurofilament subunit (NF-H) entered SDS-containing gels after exposure to aluminum lactate but migrated aberrantly as a long high-molecular-weight streak. Migration of the 160-kDa α-chymotryptic cleavage product of NF-H, which contains the higher phosphorylated tail domain, was also prevented from migrating into SDS-containing gels by AlCl3. Dephosphorylation of NF-H and the middle-molecular-weight neurofilament subunit (NF-M) eliminated these effects on gel migration. EDTA, EGTA, MgCl2, CaCl2, or FeCl3 had no effect on NF-H or NF-M migration; furthermore, preincubation with, or simultaneous exposure to, CaCl2 or FeCl3 did not alter the effect of AlCl3. One interpretation of these results is that Al3+ interacts with phosphate groups on extensively phosphorylated C-terminal sidearms of NFPs, resulting in intermolecular cross-linking. These findings demonstrate a direct effect of aluminum on NFPs and provide a possible mechanism for neurofilament accumulation in perikarya during aluminum intoxication.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1471-4159.1992.tb09753.x
