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Microtubule-associated protein tau. Abnormal phosphorylation of a non-paired helical filament pool in Alzheimer disease
Köpke E, Tung YC, Shaikh S, Alonso AC, Iqbal K, Grundke-Iqbal I.. The Journal of biological chemistry, 1993-11-01
Topic: Disease mechanisms in lab and animal studies
The major protein subunit of the paired helical filaments (PHF) of Alzheimer disease (AD) is the microtubule-associated protein tau. Tau is a family of phosphopolypeptides that are abnormally phosphorylated in PHF. In this study, a non-PHF pool of tau abnormally phosphorylated at Ser-199/202, and tau not phosphorylated at this site (AD P-tau and AD tau, respectively) were isolated from the 27,000 x g to 200,000 x g fraction of AD brain homogenate by extraction in 8 M urea, followed by dialysis against Tris buffer. AD P-tau and AD tau were further purified and separated from each other by acid precipitation, glial fibrillary acidic protein affinity chromatography, and phosphocellulose chromatography. The resulting AD P-tau and AD tau preparations were free of cytoskeletal proteins, ubiquitin, and beta-amyloid peptide. Immunochemical and morphological analysis of AD P-tau preparations revealed that most of the protein was of non-PHF origin. The AD P-tau was about 3-4-fold (approximately 8 mol P04/mol protein, M(r) 41,318) more phosphorylated than cytosolic tau from AD and control brains. Unlike PHF, the AD P-tau lacked ubiquitin. In AD brain the levels of cytosolic tau were about half of those in control aged cases. These findings suggest that the abnormal phosphorylation of tau in AD occurs in the cytosol.
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APA 7th
Köpke, E., Tung, Y. C., Shaikh, S., Alonso, A. C., Iqbal, K., & Grundke-Iqbal, I. (1993). Microtubule-associated protein tau. Abnormal phosphorylation of a non-paired helical filament pool in Alzheimer disease. The Journal of biological chemistry. https://doi.org/10.1016/s0021-9258(20)80536-5
Vancouver
Köpke E, Tung YC, Shaikh S, Alonso AC, Iqbal K, Grundke-Iqbal I. Microtubule-associated protein tau. Abnormal phosphorylation of a non-paired helical filament pool in Alzheimer disease. The Journal of biological chemistry. 1993. doi:10.1016/s0021-9258(20)80536-5. PMID: 8226987.
BibTeX
@article{kopke1993-8226987,
author = {Köpke, E. and Tung, Y. C. and Shaikh, S. and Alonso, A. C. and Iqbal, K. and Grundke-Iqbal, I.},
title = {{Microtubule-associated protein tau. Abnormal phosphorylation of a non-paired helical filament pool in Alzheimer disease}},
journal = {The Journal of biological chemistry},
year = {1993},
doi = {10.1016/s0021-9258(20)80536-5},
pmid = {8226987},
url = {https://doi.org/10.1016/s0021-9258(20)80536-5}
}
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Key findings
- Immunochemical and morphological analysis of AD P-tau preparations revealed that most of the protein was of non-PHF origin.
- These findings suggest that the abnormal phosphorylation of tau in AD occurs in the cytosol.
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Study details
- Evidence strengthLow
How this study scored 36/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, effect reported, studied in people and randomized / blinded because the record does not state it. We have no data on journal's citation record, times cited, citations per year, impact for its field and year, cited by studies here, still being cited, senior author's track record, institution's track record and multicenter collaboration, so those were left out: it earned 21 of the 58 points we could judge it on, which is 36 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (The Journal of biological chemistry) |
| Journal's citation record | — / 4 | No journal record from OpenAlex — left out of this score |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 1993 — older than 20 years, still counted |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomized / blinded | 0 / 2 | No randomization or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | — / 7 | No citation count (not found in OpenAlex) — left out of this score |
| Citations per year | — / 5 | No citation count or no year — left out of this score |
| Impact for its field and year | — / 6 | No field-weighted citation impact (OpenAlex has none yet) — left out of this score |
| Cited by studies here | — / 6 | Not yet checked against this library's citation graph — left out of this score |
| Still being cited | — / 4 | No yearly citation counts — left out of this score |
| Senior author's track record | — / 4 | Senior author's record not available — left out of this score |
| Institution's track record | — / 3 | No institution listed in OpenAlex — left out of this score |
| Multicenter collaboration | — / 3 | Institutions not listed — left out of this score |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 8226987) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 21 / 58 | Scored on 11 of 20 parts. We have no data for the rest, so they are left out: 21 of the 58 points we could judge it on is 36 out of 100. |
| Total | 36 / 100 | — |
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