Two microtubule-associated proteins, tau and the high molecular weight microtubule-associated protein 2 (MAP 2), were purified from rat brain microtubules. Addition of either protein to pure tubulin caused microtubule assembly. In the presence of tau and 10 microM vinblastine, tubulin aggregated into spiral structures. If tau was absent, or replaced by MAP 2, little aggregation occurred in the ...

Tau is a family of closely related proteins known for its ability to copolymerize with tubulin, inducing the formation of microtubules. When tau was stripped of phosphate by treatment with alkaline phosphatase it underwent a pronounced change in electrophoretic mobility, probably reflecting a conformational change. The dephosphorylated tau promoted significantly more rapid and more extensive po...

Several cytoskeletal polypeptides as well as the protein ubiquitin have been implicated as components of the neurofibrillary tangles of Alzheimer disease. We have examined the relationship of ubiquitin staining with immunoreactivity for some of these proteins, both in frozen sections and in cytoskeletal fractions of Alzheimer brain material. We noted (i) antibodies specific solely for neurofila...

Molecular chaperones regulate the aggregation of a number of proteins that pathologically misfold and accumulate in neurodegenerative diseases. Identifying ways to manipulate these proteins in disease models is an area of intense investigation; however, the translation of these results to the mammalian brain has progressed more slowly. In this study, we investigated the ability of one of these ...

In the brain, an excessive amount of zinc promotes the deposition of β-amyloid proteins and the intraneuronal accumulation of neurofibrillary tangles composed of hyperphosphorylated tau proteins. These consequences are key neuropathological traits that reflect Alzheimer's disease. Egb761, a standardized Ginkgo biloba extract, is a powerful antioxidant known to exhibit neuroprotective actions. I...

Subcellular mRNA localization, a fundamental mechanism for regulating gene expression, leads to local protein translation that results in the generation of neuronal cell polarity. In this study, we have used P19 embryonic carcinoma cells, which are amenable to transfection, and selection of clonal stable cell lines that are not overexpressing the constructs. We identified the 3' untranslated re...

Motivated by experimental results on the interplay between molecular motors and tau proteins, we extend lattice-based models of intracellular transport to include a second species of particle which locally influences the motor-filament attachment rate. We consider various exactly solvable limits of a stochastic multiparticle model before focusing on the low-motor-density regime. Here, an approx...

Neurofibrillary tangles and senile plaques are the principal pathological features of Alzheimer disease. Neurofibrillary tangles and the neurites of senile plaques contain paired helical filaments (PHF) that consist of two 10-nm filaments twisted into a double helix. The precursor proteins of PHF are not fully known. To identify these precursors, numerous immunochemical studies have been carrie...

A proteína Tau faz parte da família das proteínas associadas aos microtúbulos (microtubule-associated proteins - MAP) e sua principal função é a de estabilizar os pela agregação tubulina. Esta atua no controle dinâmica dos durante maturação o crescimento neuritos, sendo considerada maior do citoesqueleto hiperfosforilação tem consequência nas funções biológicas morfológicas nos neurônios. O obj...

In A l z h e i m e r ’s disease, the peptidyl prolyl cis/trans isomerase Pin1 binds to phospho-Thr231 on Tau proteins and, hence, is found within degenerating neurons, where it is associated to the large amounts of abnormally phosphorylated Tau proteins. Conversely, Pin1 may re s t o re the tubulin polymerization function of these hyperphosphorylated Tau. In the present work, we investigated, b...