Regulation of Nrf2 transactivation domain activity by p160 RAC3/SRC3 and other nuclear co-regulators.
Transcription factor NF-E2-related factor 2 (Nrf2) regulates the induction of Phase II detoxifying enzymes and antioxidant enzymes in response to many cancer chemopreventive compounds. In this study, we investigated the role of receptor associated coactivator (RAC3) or steroid receptor coactivator-3 (SRC3) and other nuclear co-regulators including CBP/p300 (CREB-binding protein), CARM1(Coactivator-associated arginine methyltransferase), PRMT1(Protein arginine methyl-transferase 1), and p/CAF (p300/CBP-associated factor) in the transcriptional activation of a chimeric Gal4-Nrf2-Luciferase system containing the transactivation domain (TAD) of Nrf2 in HepG2 cells. The results indicated that RAC3 up-regulated the transactivation activity of Gal4-Nrf2-(1-370) in a dose-dependent manner. The enhancement of transactivation domain activity of Gal4-Nrf2-(1-370) by RAC3 was dampened in the presence of dominant negative mutants of RAC3. Next we studied the effects of other nuclear co-regulators including CBP/ p300, CARM1, PRMT1 and p/CAF, and the results showed that they had different level of positive effects on this transactivation domain activity of Gal4-Nrf2-(1-370). But importantly, synergistic effects of these co-regulators in the presence of RAC3/SRC3 on the transactivation activity of Gal4-Nrf2-(1-370) were observed. In summary, our present study showed for the first time that the 160 RAC3/SRC3 is involved in the functional transactivation of TAD of Nrf2 and that the other nuclear co-regulators such as CBP/p300, CARM1, PRMT1 and p/CAF can also transcriptionally activate this TAD of Nrf2 and that they could further enhance the transactivation activity mediated by RAC3/SRC3.
Lin
Wen
W
Department of Pharmaceutics, Ernest-Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, 08854, USA.
Shen
Guoxiang
G
Yuan
Xiaoling
X
Jain
Mohit R
MR
Yu
Siwang
S
Zhang
Aihua
A
Chen
J Don
JD
Kong
Ah-Ng Tony
AN
D000123:Acetyltransferases / Q000378:metabolism*; D045744:Cell Line, Tumor; D005809:Genes, Regulator; D051548:Histone Acetyltransferases; D006801:Humans; D051267:NF-E2-Related Factor 2 / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D056921:Nuclear Receptor Coactivator 3; D011485:Protein Binding; D011484:Protein-Arginine N-Methyltransferases / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism*; D015533:Transcriptional Activation; D015854:Up-Regulation; D050880:p300-CBP Transcription Factors / Q000378:metabolism
D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D009687:Nuclear Proteins; D011994:Recombinant Proteins; D012097:Repressor Proteins; D015534:Trans-Activators; C099988:PRMT1 protein, human; D011484:Protein-Arginine N-Methyltransferases; C119966:coactivator-associated arginine methyltransferase 1; D000123:Acetyltransferases; D051548:Histone Acetyltransferases; C538866:NCOA3 protein, human; D056921:Nuclear Receptor Coactivator 3; D050880:p300-CBP Transcription Factors