Fig. 7: SREBP1 regulates Nrf2 stability via Keap1-mediated ubiquitination.

A Nrf2 mRNA expression in SREBP1-silenced ovarian cancer cells was measured by qPCR. B IF staining demonstrated Nrf2 expression in SREBP1-silenced ovarian cancer cells (Scale bar = 20 µm). C Subcellular localization of Nrf2 in SREBP1-silenced ovarian cancer cells was analyzed by Western blotting. D Keap1 protein levels in SREBP1-silenced ovarian cancer cells were examined by western blotting. E Nrf2 expression was assessed by Western blotting in sh-SREBP1 ovarian cancer cells following 1 h treatment with or without MG132 (5 μM). Control cells were maintained under normal culture conditions. F In ovarian cancer cells, 10 μM chloramphenicol (CHX) was administered at 0, 15, 30, and 45 min to assess the stability of Nrf2 protein in control or SREBP1-silenced cells, validated by Western blot analysis. G Nrf2 ubiquitination was examined by immunoprecipitation using anti-Nrf2 antibody in SREBP1-silenced ovarian cancer cells, followed by Western blot detection of ubiquitin in the pulldown samples. Data are presented as the mean ± SD of three independent experiments. p-values in panels: *p < 0.05, **p < 0.01.