| Transcription factor 11 (TCF11) is a basic leucine zipper transcription factor. It is also referred to as Nuclear factor E2-related factor 1 (NRF1). TCF11 was initially reported to activate erythroid-specific, human globin gene expression (1). It plays an essential role during embryonic development (2). It also associates with other transcription factors, such as Jun proteins, to transcriptionally control antioxidant response element (ARE)-mediated expression in response to antioxidants and xenobiotics (3-5). TCF11 has been shown to regulate proteasomal degradation and mediate the proteasome recovery pathway after proteasome inhibition (6,7). TCF11 is ubiquitously expressed (8) and several isoforms have been reported. The 120 kDa form exists in the endoplasmic reticulum (ER) membrane under normal conditions. Upon proteasome inhibition, TCF11 translocates to the nucleus (9). The 65 kDa N-terminal-truncated form is constitutively localized to the nucleus (10,11). TCF11 protein levels are regulated by ubiquitination and proteasomal-mediated degradation (12); proteasome inhibitors stabilize TCF11. |
