Function expansion of antitumor transcriptional activator NFE2L1 by the original discovery of its non-transcription factor activity

Abstract

ABSTRACT Antitumor transcription activator NFE2L1, with the functions to regulate redox homeostasis, protein turnover, and material metabolism, plays an important role in embryonic development and specialization of tissue and organ functions. Deficiency of NFE2L1 gene in different regions yields distinct phenotypes, suggesting that NFE2L1 may have a transcription factor-independent function. Here we originally discovered the non-transcription factor activity of NFE2L1 by constructing a truncated protein-NFE2L1 ΔC without 152 aa at the C-terminus which lost the transcription factor activity. The regulation of NFE2L1 on redox homeostasis, proteasome function, and immune response mainly depends on its transcription activator function in nucleus, while the regulation on metabolism, ribosome function, and canceration is germanely to its non-transcription factor activity in cytoplasm. Surprisingly, the results indicated the tumor suppressive effect of NFE2L1 by repression of Wnt/β-catenin signaling in a non-transcription factor manner, indicating the potential value of NFE2L1 as a therapeutic target in clinical cancer treatment independent of its transcription factor activity. Our observations reveal the non-transcription factor activity of NFE2L1 for the first time, and lay foundation for the basic and applied research of NFE2L1.