Conclusions
Our data suggest TRIM22 to repress protein translation preferably of some specific mRNAs. Taken together, we show that TRIM22 represses translation by inhibiting the binding of eIF4E to eIF4G, suggesting a mechanism for regulation of protein translation, which may be of importance in response to p53 and/or IFN signalling.
Results
Here, we demonstrate that TRIM22 directly or indirectly interacts with the eukaryotic translation initiation factor (eIF)4E, and inhibits the binding of eIF4E to eIF4G, thus disturbing the assembly of the eIF4F complex, which is necessary for cap-dependent translation. Furthermore, TRIM22 exerts a repressive effect on luciferase reporter protein levels and to some extent on radiolabelled methionine incorporation. Even though all nuclear mRNAs are capped, some are more dependent on eIF4F than others for translation. The translation of one of these mRNAs, IRF-7C, was indeed found to be repressed in the presence of TRIM22. Conclusions: Our data suggest TRIM22 to repress protein translation preferably of some specific mRNAs. Taken together, we show that TRIM22 represses translation by inhibiting the binding of eIF4E to eIF4G, suggesting a mechanism for regulation of protein translation, which may be of importance in response to p53 and/or IFN signalling.