Figure 8. Physical interactions between SREBP-1c, NF-Y and Sp1 are not required for PUFA-dependent decrease in Fasn transcription.

Immunoprecipitation (IP) of nuclear extracts from livers of rats on each diet were conducted with NF-Y, Sp1 and SREBP-1 antibodies to evaluate the effects of FO on protein–protein interactions involving SREBP-1c, NF-Y and Sp1. In conjunction with immunoprecipitation using antibodies specific for NF-YA, Sp1 and SREBP-1, we also performed immunoprecipitations using equivalent amounts of either normal goat IgG (the source of the NF-YA IP antibody) and normal rabbit IgG (the source of the Sp1 and SREBP-1c IP antibodies) to control for the formation of non-specific complexes. The supernatants and pellets from each immunoprecipitation were retained and Western blotted (WB) for NF-YA, Sp1 and SREBP-1c, and relative band intensity was analysed on the Versadoc system (Bio-Rad Laboratories). (A) Western blots of NF-YA (top panel) and SREBP-1c (bottom panel) on pellets and supernatants from representative samples of each group immunoprecipitated with the NF-YA antibody. (B) Western blots of SP1 (top panel) and SREBP-1c (bottom panel) on pellets and supernatants from representative samples of each group immunoprecipitated with the Sp1 antibody. (C) Western blots of SREBP-1c (top panel), Sp1 (middle panel) and NF-YA (bottom panel) on pellets and supernatants from representative samples of each group immunoprecipitated with the SREBP-1 antibody.