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Author Notes:

Address correspondence to: Nicholas T. Seyfried, Department of Biochemistry, Emory University School of Medicine, 1510 Clifton Road, Atlanta, Georgia 30322, USA. Tel. 404.712.9783, nseyfri@emory.edu.

We would like to thank Dr. Tauseef Butt (Life Sensors) for providing the Biotin-TUBE1 reagent.

Subjects:

Research Funding:

This study was provided by grants from the Accelerating Medicine Partnership AD (U01AG046161–02, the National Institute on Aging (R21AG054206, 5R01AG053960, RF1AG057470, and RF1AG057471, the NINDS Emory Neuroscience Core (P30NS055077), and the Emory Alzheim er’s Disease Research Center (P50AG025688).

N.T.S. was supported in part by a Biomarkers Across Neurodegenerative Grant (11060) funded by the Alzheim er’s Association (ALZ), Alzheim er’s Research UK (ARUK), The Michael J. Fox Foundation for Parkinson’s Research (MJFF), and the W eston Brain Institute.

M.H.A. was supported by an NIH training grant T32 NS00748018.

Keywords:

  • Science & Technology
  • Life Sciences & Biomedicine
  • Biochemical Research Methods
  • Biochemistry & Molecular Biology
  • mass spectrometry
  • neurodegeneration
  • post-translational modifications
  • protein aggregation
  • proteomics
  • ubiquitylation
  • PROTEIN AGGREGATION
  • TAU-PROTEIN
  • POSTTRANSLATIONAL MODIFICATIONS
  • NEURODEGENERATIVE DISEASES
  • UBIQUITINATION SITES
  • PROTEASOME PATHWAY
  • MASS-SPECTROMETRY
  • BINDING ENTITIES
  • APOLIPOPROTEIN-E
  • GLOBAL ANALYSIS

Quantitative Analysis of the Brain Ubiquitylome in Alzheimer's Disease

Journal Title:

Proteomics

Volume:

Volume 18, Number 20

Publisher:

, Pages e1800108-e1800108

Type of Work:

Article | Post-print: After Peer Review

Abstract:

Several neurodegenerative diseases including Alzheimer's Disease (AD) are characterized by ubiquitin-positive pathological protein aggregates. Here, an immunoaffinity approach is utilized to enrich ubiquitylated isopeptides after trypsin digestion from five AD and five age-matched control postmortem brain tissues. Label-free MS-based proteomic analysis identifies 4291 unique ubiquitylation sites mapping to 1682 unique proteins. Differential enrichment analysis shows that over 800 ubiquitylation sites are significantly altered between AD and control cases. Of these, ≈80% are increased in AD, including seven poly ubiquitin linkages, which is consistent with proteolytic stress and high burden of ubiquitylated pathological aggregates in AD. The microtubule associated protein Tau, the core component of neurofibrillary tangles, has the highest number of increased sites of ubiquitylation per any protein in AD. Tau poly ubiquitylation from AD brain homogenates is confirmed by reciprocal co-immunoprecipitation and by affinity capture using tandem ubiquitin binding entities. Co-modified peptides, with both ubiquitylation and phosphorylation sites, are also enriched in AD. Notably, many of the co-modified peptides mapped to Tau within KXGS motifs in the microtubule binding region suggesting that crosstalk between phosphorylation and ubiquitylation occurs on Tau in AD. Overall, these findings highlight the utility of MS to map ubiquitylated substrates in human brain and provides insight into mechanisms underlying pathological protein posttranslational modification in AD.

Copyright information:

© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

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