Figure 2: Protein expression of NRF1 and p40-NRF2 in western blot, fractionated cell lysates from IPC-298 melanoma cells, β-actin, and PCNA (proliferating cell nuclear antigen) serve as loading and fractioning controls. NRF1 detected with an antibody targeting N-terminal domain is expressed in membranous fraction, and NRF1 detected with an antibody targeting C-terminal domain is expressed mostly in the nuclear fraction. p40-NRF2 is expressed in the cytoplasmic, membranous, and nuclear fractions.