NUCLEAR FACTOR-1 IS ESSENTIAL FOR THE EXPRESSION OF STEAROYL-COA DESATURASE-1 GENE DURING PREADIPOCYTE DIFFERENTIATION

Stearoyl CoA desaturase gene 1 (SCD1) is a Delta(9) desaturase that is transcriptionally activated during the differentiation of 3T3-L1 prea dipocytes into adipocytes. We have demonstrated that a SCD1/BP region in SCD1 proximal prornoter (-114 to -86 bp) is essential for the trans criptional activation of this gene during differentiation. Mutation in this region abolished the basal activity of the proximal promoter of SCD1, and also failed to induce transcription in response to the diffe rentiation cocktail in transfected cells. The SCD1/BP region contains a TGGCA sequence at -90 bp from the transcription start site. Using co mpetitor oligonucleotides and nuclear factor 1 (NF1)-specific antibodi es in gel shift assays, we have shown that in preadipocytes, a NF1 pro tein binds to this TGGCA sequence. On MDI-induced differentiation of p readipocyte into adipocyte, an additional DNA-protein complex appeared . The appearance of a new NF1 complex is related to the differentiatio n-specific transcriptional activation of the SCD1 gene. This is the fi rst report to show a differentiation-related change in NF1 protein bin ding during preadipocyte differentiation. (C) 1998 Elsevier Science B. V. All rights reserved.