Mouse translation elongation factor eEF1A-2 interacts with Prdx-I to protect cells against apoptotic death induced by oxidative stress

J Cell Biochem. 2007 Feb 1;100(2):267-78. doi: 10.1002/jcb.20969.

Abstract

eEF1A-1 and eEF1A-2 are two isoforms of translation elongation factor eEF1A. In adult mammalian tissues, isoform eEF1A-1 is present in all tissues except neurons, cardiomyocytes, and myotubes, where its isoform, eEF1A-2, is the only form expressed. Both forms of eEF1A have been characterized to function in the protein elongation step of translation, and eEF1A-1 is shown to possess additional non-canonical roles in actin binding/bundling, microtubule bundling/severing, and cellular transformation processes. To study whether eEF1A-2 has similar non-canonical functions, we carried out a yeast two-hybrid screening using a full sequence of mouse eEF1A-2 as bait. A total of 78 hits, representing 23 proteins, were identified and validated to be true positives. We have focused on the protein with the highest frequency of hits, peroxiredoxin I (Prdx-I), for in-depth study of its functional implication for eEF1A-2. Here we show that Prdx-I coimmunoprecipitates with eEF1A-2 from extracts of both cultured cells and mouse tissues expressing this protein, but it does not do so with its isoform, eEF1A-1, even though the latter is abundantly present. We also report that an eEF1A-2 and Prdx-I double transfectant increases resistance to peroxide-induced cell death as high as 1 mM peroxide treatment, significantly higher than do single transfectants with either gene alone; this protection is correlated with reduced activation of caspases 3 and 8, and with increased expression of pro-survival factor Akt. Thus, our results suggest that eEF1A-2 interacts with Prdx-I to functionally provide cells with extraordinary resistance to oxidative stress-induced cell death.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Apoptosis* / drug effects
  • Caspase 3 / metabolism
  • Caspase 8 / metabolism
  • Enzyme Activation / drug effects
  • Heat-Shock Proteins / genetics
  • Heat-Shock Proteins / metabolism*
  • Hydrogen Peroxide / pharmacology
  • Immunoprecipitation
  • Mice
  • NIH 3T3 Cells
  • Organ Specificity
  • Oxidative Stress*
  • Peptide Elongation Factor 1 / genetics
  • Peptide Elongation Factor 1 / metabolism*
  • Peroxidases / genetics
  • Peroxidases / metabolism*
  • Peroxiredoxins
  • Protein Binding
  • Proto-Oncogene Proteins c-akt / metabolism

Substances

  • Eef1a2 protein, mouse
  • Heat-Shock Proteins
  • Peptide Elongation Factor 1
  • Hydrogen Peroxide
  • Peroxidases
  • Peroxiredoxins
  • Prdx1 protein, mouse
  • Proto-Oncogene Proteins c-akt
  • Caspase 3
  • Caspase 8