mTor is a signaling hub in cell survival: a mass-spectrometry-based proteomics investigation

J Proteome Res. 2014 May 2;13(5):2433-44. doi: 10.1021/pr500192g. Epub 2014 Apr 14.

Abstract

mTor plays a central role in controlling protein homeostasis and cell survival. Recently, we have demonstrated that perturbations of mTor signaling are implicated in Alzheimer's disease (AD) and that mTor complex 1 (mTorC1) is involved in the formation of toxic phospho-tau. Therefore, we employed mass-spectrometry-based proteomics to identify specific protein expression changes in relation with cell survival in human neuroblastoma SH-SY5Y cells expressing genetically modified mTor. Cell death in SH-SY5Y cells was induced by moderate serum deprivation. Using flow cytometry we observed that up-regulated mTor complex 2 (mTorC2) increases the number of viable cells. By using a combination approach of proteomic and enrichment analysis we have identified several proteins (Thioredoxin-dependent peroxide reductase, Peroxiredoxin-5, Cofilin 1 (non-muscle), Annexin A5, Mortalin, and 14-3-3 protein zeta/delta) involved in mitochondrial integrity, apoptotosis, and pro-survival functions (caspase inhibitor activity and anti-apoptosis) that were significantly altered by mTor activity modulation. The major findings of this study are the implication of mTorC2 but not mTorC1 in cell viability modulation by activating the pro-survival machinery. Taken together, these results suggest that up-regulated mTorC2 might be playing an important role in promoting cell survival by suppressing the mitochondria-caspase-apoptotic pathway in vitro.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis
  • Blotting, Western
  • Caspases / metabolism
  • Cell Line, Tumor
  • Cell Survival
  • Humans
  • Mechanistic Target of Rapamycin Complex 1
  • Mechanistic Target of Rapamycin Complex 2
  • Mitochondria / metabolism
  • Multiprotein Complexes / metabolism
  • Neuroblastoma / genetics
  • Neuroblastoma / metabolism
  • Neuroblastoma / pathology
  • Phosphorylation
  • Proteins / metabolism*
  • Proteomics / methods*
  • Signal Transduction*
  • TOR Serine-Threonine Kinases / genetics
  • TOR Serine-Threonine Kinases / metabolism*
  • Tandem Mass Spectrometry / methods*
  • tau Proteins / metabolism

Substances

  • Multiprotein Complexes
  • Proteins
  • tau Proteins
  • MTOR protein, human
  • Mechanistic Target of Rapamycin Complex 1
  • Mechanistic Target of Rapamycin Complex 2
  • TOR Serine-Threonine Kinases
  • Caspases