About this item:

619 Views | 0 Downloads

Author Notes:

Corresponding Authors: Allan I. Levey, Department of Neurology, alevey@emory.edu, and James J. Lah, Department of Neurology, jlah@emory.edu, and Junmin Peng, Department of Human Genetics, jpeng@genetics.emory.edu, Emory University School of Medicine, Atlanta, Georgia 30322

Authors contributed equally to this work.

Reprinted (adapted) with permission from Herskowitz, J. H., Seyfried, N. T., Duong, D. M., Xia, Q., Rees, H. D., Gearing, M., Peng, J., et al. (2010). Phosphoproteomic Analysis Reveals Site-Specific Changes in GFAP and NDRG2 Phosphorylation in Frontotemporal Lobar Degeneration. Journal of Proteome Research, 9(12), 6368–6379. doi:10.1021/pr100666c. Copyright 2010 American Chemical Society.

Subjects:

Research Funding:

National Institute on Aging : NIA

National Institute of Neurological Disorders and Stroke : NINDS

Keywords:

  • Frontotemporal dementia
  • phosphorylation
  • immobilized metal-affinity chromatography (IMAC)
  • proteomics
  • neurodegeneration

Phosphoproteomic analysis reveals site-specific changes in GFAP and NDRG2 phosphorylation in frontotemporal lobar degeneration

Tools:

Journal Title:

Journal of Proteome Research

Volume:

Volume 9, Number 12

Publisher:

, Pages 6368-6379

Type of Work:

Article | Post-print: After Peer Review

Abstract:

Frontotemporal lobar degeneration (FTLD) is a progressive neurodegenerative disease characterized by behavioral abnormalities, personality changes, language dysfunction, and can co-occur with the development of motor neuron disease. One major pathological form of FTLD is characterized by intracellular deposition of ubiquitinated and phosphorylated TAR DNA binding protein-43 (TDP-43), suggesting that dysregulation in phosphorylation events may contribute to disease progression. However, to date systematic analysis of the phosphoproteome in FTLD brains has not been reported. In this study we employed immobilized metal affinity chromatography (IMAC) followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify phosphopeptides from FTLD and age-matched control postmortem human brain tissue. Using this approach we identified 786 phosphopeptides in frontal cortex (control and FTLD), in which the population of phosphopeptides represented approximately 50% of the total peptides analyzed. Label free quantification using spectral counts revealed six proteins with significant changes in the FTLD phosphoproteome. N-myc-downstream regulated gene 2 (NDRG2) and glial fibrillary acidic protein (GFAP) had an increased number of phosphospectra in FTLD, whereas microtubule associated protein 1A (MAP1A), reticulon 4 (RTN4; also referred to as neurite outgrowth inhibitor (Nogo)), protein kinase C gamma (PRKCG), and heat shock protein 90kDa alpha, class A member 1(HSP90AA1) had significantly fewer phosphospectra compared to control brain. To validate these differences, we examined NDRG2 phosphorylation in FTLD brain by immunoblot analyses, and using a phosphoserine-13 (pSer13) GFAP monoclonal antibody we show an increase in pSer13 GFAP levels by immunoblot concomitant with increased overall GFAP levels in FTLD cases. These data highlight the utility of combining proteomic and phosphoproteomic strategies to characterize postmortem human brain tissue.
Export to EndNote