Reciprocal regulation of the human sterol regulatory element binding protein (SREBP)-1a promoter by Sp1 and EGR-1 transcription factors

A simple promoter containing two Sp1 sites controls the expression of sterol-regulatory-element-binding protein 1a (SREBP-1a).

The mammalian gene for SREBP-1 (sterol-regulatory-element-binding protein 1) contains two promoters that control the production of two proteins, SREBP-1a and -1c, and each contains a unique N-terminal transcriptional activation domain, but they are otherwise identical. The relative level of each mRNA varies from tissue to tissue and they respond differently to regulatory stimuli. SREBP-1c is mo...

[Sterol regulatory element binding protein (SREBP)].

Insulin activates human sterol-regulatory-element-binding protein-1c (SREBP-1c) promoter through SRE motifs.

In the present study, we aimed to decipher the mechanisms involved in the transcriptional effect of insulin on the SREBP-1c specific promoter of the human srebf-1 gene. Using luciferase reporter gene constructs in HEK-293 cells (human embryonic kidney cells), we demonstrated that the full effect of insulin requires the presence of SREs (sterol response elements) in the proximal region of the pr...

Sterol regulatory element binding protein-1a transactivates 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase gene promoter.

6-Phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB) catalyzes the synthesis and degradation of fructose-2,6-bisphosphate, a key modulator of glycolysis-gluconeogenesis. To gain insight into the molecular mechanism behind hormonal and nutritional regulation of PFKFB expression, we have cloned and characterized the proximal promoter region of the liver isoform of PFKFB (PFKFB1) from gilt...

Sterol regulatory element binding proteins (SREBP)-1a and SREBP-2 are linked to the MAP-kinase cascade.

The classic sterol regulatory cis element (sre-1) in the LDL receptor promoter mediates sterol regulatory element binding protein (SREBP)-binding and the effects of insulin and platelet derived growth factor (PDGF). To elucidate whether SREBP-1a and SREBP-2 play a direct role in insulin and PDGF action, stable cell lines of HepG2 deficient in either SREBP-1 or SREBP-2 were used. Transfection of...