Mouse translation elongation factor eEF1A-2 interacts with Prdx-I to protect cells against apoptotic death induced by oxidative stress.
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.
Chang
Ruying
R
Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, Kentucky 40202, USA.
Wang
Eugenia
E
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000378:metabolism; D053181:Caspase 8 / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D047468:Immunoprecipitation; D051379:Mice; D041681:NIH 3T3 Cells; D009928:Organ Specificity; D018384:Oxidative Stress; D020648:Peptide Elongation Factor 1 / Q000235:genetics / Q000378:metabolism*; D010544:Peroxidases / Q000235:genetics / Q000378:metabolism*; D054464:Peroxiredoxins; D011485:Protein Binding; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism
C503235:Eef1a2 protein, mouse; D006360:Heat-Shock Proteins; D020648:Peptide Elongation Factor 1; D006861:Hydrogen Peroxide; D010544:Peroxidases; D054464:Peroxiredoxins; C489899:Prdx1 protein, mouse; D051057:Proto-Oncogene Proteins c-akt; D053148:Caspase 3; D053181:Caspase 8