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Query: UNIPROT:P10636 (tau protein)
 5,110 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tau, a major class of microtubule-associated proteins, consists of a family of proteins that are heterogeneous in molecular weight. The presence of internal deletions in previously described cDNA clones for murine and bovine tau suggested that alternative splicing of transcripts could account for the protein size heterogeneity. Analysis of the exon-intron structure of the bovine tau gene provided sequence information necessary to detect new variants of tau transcripts by in vitro amplification techniques. The variant transcripts found corresponded to mRNA species missing one or more exons, which suggested that by skipping various exons during mRNA splicing, a family of proteins is generated. Four major tau protein isoforms isolated from bovine brain were identified by comparison with translation products of cDNA constructs and the use of antisera raised against synthetic peptides. These studies provide reagents and a basis for analyzing potentially altered forms of tau proteins in brains of patients with Alzheimer's disease.
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PMID:Structure of the bovine tau gene: alternatively spliced transcripts generate a protein family. 249 50

Amino acid sequencing of a CNBr digest of the tau protein isolated from bovine brain revealed an amino acid sequence of 17 residues, Pro-Gly-Leu-Lys-Glu-Ser-Pro-Leu-Gln-Ile-Gly-Ala-Ala-Pro-Gly-Leu-Lys, which we call peptide I, with heterogeneity at position 11 of glycine (peptide Ia) and proline (peptide Ib); peptide I showed no homology with the previously reported cDNA-derived mouse and human tau sequences. Antisera raised to synthetic peptides corresponding to peptides Ia and Ib labeled all the bovine tau polypeptides recognized by other monoclonal and polyclonal antibodies to bovine tau. Antisera to peptide Ib did not label any mouse tau polypeptides; however, an anti-Ia antiserum labeled two of the four mouse tau polypeptides. Antisera to both peptides labeled paired helical filaments (PHF) as neurofibrillary tangles, plaque neurites, and neuropil threads in Alzheimer disease brain and PHF polypeptides on immunoblots. Immunostaining with anti-Ia antisera of PHF in tissue sections and PHF polypeptides, but not bovine tau, on immunoblots was markedly increased when pretreated with alkaline phosphatase. These studies suggest that (i) the amino acid sequences of some isoforms of tau peptide might be different from that predicted from cDNAs, (ii) a tau peptide that is absent in the predicted sequences is present in PHF in Alzheimer disease, and (iii) tau in PHF is abnormally phosphorylated.
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PMID:Identification and localization of a tau peptide to paired helical filaments of Alzheimer disease. 250 95

We report our ongoing work to characterize the molecular nature of neurofibrillary tangles (NFT). An epitope map of tau protein using monoclonal antibodies that crossreact with NFT reveals the presence of epitopes that span the entire tau molecule from the amino terminus to the carboxy terminus. Several antibodies that recognize tau protein including Alz50 do not recognize primary amino acid sequence but are directed either against a post-translational modification or a complex higher order structure. The importance of tau protein in the development of the pathology is underscored by the extent of the tau-reactive neuritic lesions. These dystrophic neurites or "curly fibers" extend well beyond the classical distributions of the senile plaques and NFT. Furthermore, the neuropil lesion is considerably more extensive than either the senile plaques or neurofibrillary tangles. One of the features of the dystrophy in Alzheimer's disease is widespread neuronal sprouting characteristic of dystrophic neurites and tangle-bearing cells.
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PMID:Along the way to a neurofibrillary tangle: a look at the structure of tau. 250 56

The paired helical filament, the principal component of the neurofibrillary tangles characteristic of Alzheimer's disease, is shown to consist of two structurally distinct parts. An external fuzzy region can be removed by pronase treatment to leave a pronase-resistant morphologically recognizable core. A monoclonal antibody has been raised which both decorates the core and labels peptide fragments extracted from the core. Amino acid sequence derived from such peptides was used to design oligonucleotide probes with which cDNA libraries were screened and clones coding for the corresponding proteins were isolated. The sequences proved to code for two isoforms of human microtubule-associated protein tau, which contained respectively three or four tandem repeats of 31 or 32 amino acids each with a characteristic Pro-Gly-Gly-Gly motif. The patterns of mRNA expression for the two isoforms were found to be stage and cell-type specific but were apparently unaltered in Alzheimer's disease. The repeat region of tau is believed to be the microtubule binding domain and it is this region of the molecule which is tightly and specifically bound in the core of the paired helical filament.
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PMID:The repeat region of microtubule-associated protein tau forms part of the core of the paired helical filament of Alzheimer's disease. 250 57

Submitted for the study were 116 autopsy brains, from 65 non-demented people, 24 patients with dementia of Alzheimer type (DAT) and 27 patients with vascular dementia, aged between 50 s and 100 s. Formalin-fixed, paraffin-embedded coronal sections of the brains at the level of the lateral geniculate body were immunohistochemically stained with the avidin-biotin-peroxidase complex procedure, using the anti-bodies to tau protein purified from human brains (anti-tau) as the primary antibodies. Alzheimer neurofibrillary tangles (NFTs) which were specifically and selectively stained by anti-tau were semiquantitatively counted in the areas of the hippocampus, parahippocampal gyrus and lateral occipitotemporal gyrus. The results were as follows: 1) In non-demented subjects, NFTs in the hippocampus and parahippocampal gyrus were scanty in the 50 s: they increased markedly after 60 years until 90 as the patients' age increased; they tended to decrease over 90 years. In contrast, NFTs in the lateral occipitotemporal gyrus remained none or scanty, always less than 10/mm2 field, throughout the ages between 50 s and 100 s. 2) In DAT cases, NFTs in the hippocampus and parahippocampal gyrus were numerous in all cases at any ages. NFTs in the lateral occipitotemporal gyrus were also many, and always more than 10/mm2 in all cases except a few ones over 80 years of age. The numbers of NFTs of the three areas were significantly higher in DAT cases than in non-demented subjects. 3) In most cases of vascular dementia, the density and distribution pattern of NFTs were essentially similar to those of non-demented subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[A semiquantitative study on Alzheimer neurofibrillary tangles demonstrated immunohistochemically with anti-tau antibodies, in the brains of non-demented and demented old people]. 250 32

Tau protein is a microtubule-associated protein implicated in the spatial and temporal specification of microtubules and has been found in the neurofibrillary tangles of Alzheimer's disease. Determination of tau protein structure has revealed three 18 amino acid repeated sequences hypothesized to be tubulin binding sites. Using tau cDNA clones from human fetal brain, we employed E. coli expression systems to synthesize tau protein and fragments of tau protein in order to identify the microtubule binding site. A fragment containing the three repeated sequences binds microtubules, while the amino-terminal half of the protein does not bind. Fragments containing two or one repeat are also capable of binding, indicating that the basic tubulin interacting unit is one repeat.
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PMID:The microtubule binding domain of tau protein. 251 29

The antigenic components of Lewy bodies in the cerebral cortex and substantia nigra in 5 cases of diffuse Lewy body disease were examined by immunocytochemistry, using antibodies to neurofilaments (in the phosphorylated or non-phosphorylated forms); to ubiquitin; to the microtubule-associated proteins MAP1, MAP2 and tau; to isolated Alzheimer paired helical filaments, and to tubulin, in the tyrosinated and non-tyrosinated forms. Immunoreactivity with antibodies to cytoskeletal components was identical to that previously described for Lewy bodies of idiopathic Parkinson disease, with the exception that the inclusions of diffuse Lewy body disease (in both cortex and substantia nigra) were stained by an antibody to tau protein. Our findings indicate that although the inclusions found in diffuse Lewy body disease share structural and epitopic features with the inclusions of idiopathic Parkinson disease, they also have distinguishing characteristics (in addition to the differing neuronal populations involved). Also, they suggest that although the inclusions in both conditions appear similar, they probably have different pathogenetic origins.
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PMID:The presence of tau distinguishes Lewy bodies of diffuse Lewy body disease from those of idiopathic Parkinson disease. 254 30

Brains were obtained at autopsy from 24 patients with Down's syndrome, ranging in age from 13 to 71 years. Neurofibrillary tangle containing neurones of the hippocampus were stained using a Palmgren silver method and immunocytochemically (PAP) using antisera to paired helical filament protein, human tau protein and ubiquitin, as primary antibody. Counts of cells stained by each method were compared. In patients under 50 years of age, in whom only a limited number of tangle bearing cells were present, the number of profiles visualized with silver, anti-paired helical filament and anti-tau methods were similar. However, in patients over 50 years of age (and in certain of those under 50), in whom numerous tangles were present, the number of cell profiles visualized with silver and anti-paired helical filament methods were still similar though anti-tau detected fewer positive cells. This was because of the increased presence, in such patients, of extracellular tangles which had "lost" anti-tau immunoreactivity. Such data suggest that although tau protein forms a major antigenic determinant of neurofibrillary tangles in Down's syndrome (as it does in Alzheimer's disease) this protein may only decorate the basic paired helical filament protein skeleton, and is removed by macrophagic activity upon neuronal death. In all patients, anti-ubiquitin revealed fewer tangles than any other method. It is possible that ubiquitin may be present only transiently, within tangles perhaps following initial formation and lasting only as long as the normal protein degradation processes remain viable within the diseased neurone.
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PMID:Immunocytochemical profile of neurofibrillary tangles in Down's syndrome patients of different ages. 255 74

In his original 1911 publication Alois Alzheimer classified neurofibrillary tangles (ANT) into three morphologically defined subgroups according to their stage of maturation. The present study shows that changes in the morphological appearance of ANT during their maturation process are accompanied by changes in their antigenic profile. As shown by several immunocytochemical studies these abnormal phosphorylated microtubule-associated protein tau and of ubiquitin. In this study, immunoreactivity for the altered tau is not only seen in a subset of tangles but also in the cytoplasm of some nerve cells lacking ANT, which we believe to be at a stage of neuronal alteration preceding the formation of compact tangles (Stage 0 tangles). Similar numbers of Stage 0 tangles are present in the brains of age-matched non-demented individuals as in Alzheimer cases, but are absent in young controls lacking ANT. In extracellular "ghost tangles", the ultimate stage of neurofibrillary degeneration, immunoreactivity for tau is accessible to antibodies only when tissue sections are pretreated with formic acid to uncover the binding sites. In contrast to tau, presence/accessibility of an epitope residing on residues 50-65 of ubiquitin recognized by a monoclonal antibody raised to paired helical filaments (3-39) increases during the maturation of ANT and is most pronounced in "ghost tangles". Appearance/uncovering of the 3-39 epitope and masking of tau reactivity during tangle maturation may reflect degradation or conformational changes in the pathological filaments due to their aging and the final loss of their parent nerve cells.
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PMID:Tau and ubiquitin immunoreactivity at different stages of formation of Alzheimer neurofibrillary tangles. 255 44

The relevance of plaques and tangles to the study of Alzheimer's disease is considered. Recent results concerning isoforms of microtubule-associated protein tau, their expression and incorporation into paired helical filaments, are discussed.
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PMID:Amyloid plaques, neurofibrillary tangles and their relevance for the study of Alzheimer's disease. 268 18


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