Direct evidence of phosphorylated neuronal intermediate filament proteins in neurofibrillary tangles (NFTs): phosphoproteomics of Alzheimer's NFTs
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Alzheimer's disease (AD) is a neurodegenerative disorder characterized by brain pathology of intracellular neurofibrillary tangles (NFTs) and extracellular amyloid plaques. NFTs contain aberrantly hyperphosphorylated Tau as paired helical filaments (PHFs). Although NFs have been shown immunohistologically to be part of NFTs, there has been debate that the identity of NF proteins in NFTs is due to the cross‐reactivity of phosphorylated NF antibodies with phospho‐Tau. Here, we provide direct evidence on the identity of NFs in NFTs by immunochemical and mass spectrometric analysis. We have purified sarkosyl‐insoluble NFTs and performed liquid chromatography/tandem mass spectrometry of NFT tryptic digests. The phosphoproteomics of NFTs clearly identified NF‐M phosphopeptides SPVPKS ∗ PVEEAK, corresponding to Ser685, and KAES ∗ PVKEEAVAEVVTITK, corresponding to Ser736, and an NF‐H phosphopeptide, EPDDAKAKEPS ∗ KP, corresponding to Ser942. Western blotting of purified tangles with SMI31 showed a 150‐kDa band corresponding to phospho‐NF‐M, while RT97 antibodies detected phospho‐NF‐H. The proteomics analysis also identified an NF‐L peptide (ALYEQEIR, EAEEEKKVEGAGEEQAAAK) and another intermediate filament protein, vimentin (FADLSEAANR). Mass spectrometry revealed Tau phosphopeptides corresponding to Thr231, Ser235, Thr181, Ser184, Ser185, Thr212, Thr217, Ser396, and Ser403. And finally, phosphopeptides corresponding to MAP1B (corresponding to Ser1270, Ser1274, and Ser1779) and MAP2 (corresponding to Thr350, Ser1702, and Ser1706) were identified. In corresponding matched control preparations of PHF/NFTs, none of these phosphorylated neuronal cytoskeletal proteins were found. These studies independently demonstrate that NF proteins are an integral part of NFTs in AD brains.—Rudrabhatla, P., Jaffe, H., Pant, H. C. Direct evidence of phosphorylated neuronal intermediate filament proteins in neurofibrillary tangles (NFTs): phosphoproteomics of Alzheimer's NFTs. FASEB J. 25, 3896–3905 (2011). www.fasebj.org
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Small quantities of MAP2 have been identified in neurofibrillary tangles.
“Nevertheless, small quantities of MAP2 have been identified in neurofibrillary tangles (34, 35), and interactome studies in human AD brain have captured MAP2 together with oligomeric tau (35, 36).”
From MAP2 caps tau fibrils and inhibits aggregation (2023) · cites this paper as [34]
Table 3 (Results; page not provided) identifies MAP2 phosphopeptides in purified neurofibrillary tangles, supporting the identification of MAP2. The paper does not quantify MAP2 as present in “small quantities”; the Discussion instead describes an abundance of phosphorylated MAP peptides. (LLM, conf=0.84)
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References 58 · Cited by 121
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- [1]1. Alzheimer A. (1907) Über eine eigenartige. Erkrankung der Hirnrinde. J. Gen. Psychiatr. (German) 64, 146–148 [Google Scholar]
- [15]15. Gambetti P., Autilio-Gambetti L., Perry G., Shecket G., Crane R. C. (1983) Antibodies to neurofibrillary tangles of Alzheimer's disease raised from human and animal neurofilament fractions. Lab. Invest. 49, 430–435 [PubMed] [Google Scholar]
- [18]18. Kosik K. S., Selkoe D. J., Sapirstein V. (1984) Possible modifications of vimentin following acquisition of triton insolubility. Biochem. Int. 4, 483–490 [PubMed] [Google Scholar]
- [52]52. Alonso Adel C., Li B., Grundke-Iqbal I., Iqbal K. (2006) Polymerization of hyperphosphorylated TAU into filaments eliminates its inhibitory activity. Proc. Natl. Acad. Sci. U. S. A. 103, 8864–8869 [DOI] [PMC free article] [PubMed] [Google Scholar]
- Authors
- Rudrabhatla, P., Jaffe, H., & Pant, H. C.
- Affiliations
- National Institutes of Health (US)
- Corresponding author
- Pant, Harish C.
- Venue
- The FASEB Journal
- Publisher
- Wiley
- Published
- 2011-08-09
- Volume
- 25
- Issue
- 11
- Pages
- 3896-3905
- ISSN
- 0892-6638 (ISSN-L)
- 1530-6860
- PMC
- PMC3205835
- OpenAlex
- W2014752627
- Cited by
- 121
- References
- 58
- Citations by year
- 2026: 2 · 2025: 6 · 2024: 7 · 2023: 8 · 2022: 19 · 2021: 9 · 2020: 7 · 2019: 6 · 2018: 6 · 2017: 6 · 2016: 7 · 2015: 10 · 2014: 5 · 2013: 11 · 2012: 11
- FWCI
- 5.89
- Type
- journal article
- Language
- en
- Open access
- green
- www.ncbi.nlm.nih.gov
- Locations
- The FASEB Journal (publishedVersion)
- PubMed Central (publishedVersion)
- PubMed (publishedVersion)
- Funders
- National Institute of Neurological Disorders and Stroke
- National Institutes of Health
- Topics
- Health Sciences › Medicine › Physiology › Alzheimer's disease research and treatments
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Skin and Cellular Biology Research
- Physical Sciences › Chemistry › Spectroscopy › Advanced Proteomics Techniques and Applications
- Keywords
- neurofibrillary tangles, Alzheimer's disease, neuronal intermediate filaments, NF-M, neurofilament heavy chain, vimentin, tau hyperphosphorylation, paired helical filaments, phosphoproteomics, MAP1B, MAP2, cytoskeletal proteins
- MeSH terms
- Aged, 80 and over, Alzheimer Disease, Humans, Intermediate Filaments, Middle Aged, Phosphopeptides, Phosphorylation, Vimentin, Neurofibrillary Tangles, tau Proteins, Proteomics, Tandem Mass Spectrometry
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