eEF1A mediates the nuclear export of SNAG-containing proteins via the exportin5-aatRNA complex

Abstract

Exportin5 mediates the nuclear export of dsRNAs including pre-miRNAs, adenoviral RNAs and tRNAs. When tRNAs are aminoacylated, the aatRNA-Exportin5 complex recruits and co-exports the translation elongation factor eEF1A. Here we show that eEF1A recruits Snail transcription factors, facilitating their export to the cytoplasm in association with the aatRNA-Exportin5 complex. Snail binds to eEF1A through the SNAG domain, a novel protein nuclear export signal (NES) present in several transcription factor families, and this binding is regulated by phosphorylation. Thus, we describe a nuclear role for eEF1A and provide a novel mechanism for protein nuclear export that attenuates the activity of SNAG-containing transcription factors.