Sterol regulatory element-binding protein 1 (SREBP-1) and Sterol regulatory element-binding protein 2 (SREBP-2) (SREBP-1; SREBP-2)

Sterol regulatory element-binding proteins (SREBP-1 and SREBP-2) are membrane-bound transcription factors of the basic helix-loop-helix-leucine zipper (bHLH-LZ) class that control the expression of genes involved in lipid homeostasis, including cholesterol and fatty acid biosynthesis. SREBP-1 is mainly involved in regulating fatty acid and triglyceride synthesis, existing as two main isoforms: SREBP-1a and SREBP-1c (from the SREBF1 gene). SREBP-2 (from the SREBF2 gene) primarily controls cholesterol metabolism. Both proteins are synthesized as precursor forms attached to the ER and nuclear envelope, requiring proteolytic activation for the mature N-terminal domain to translocate to the nucleus and regulate transcription of target genes. Their activities are regulated by sterol and lipid levels through the SCAP-Insig-SREBP pathway, providing feedback control for lipid biosynthesis in response to metabolic needs. Dysfunction of SREBPs has been implicated in a variety of diseases, including cancer, metabolic syndrome, diabetes, and cardiovascular disorders, and they are prominent targets for experimental modulation of lipid metabolism.

Other names

Sterol regulatory element-binding transcription factor 1SREBF1ADD-1 (specifically SREBP-1c)Sterol regulatory element-binding transcription factor 2SREBF2

Inhibition of SREBP activation (e.g., by blocking SCAP-mediated trafficking or proteolytic activation). Indirect inhibition of SREBP pathway by lowering sterol levels via HMG-CoA reductase inhibitors (statins), which can modulate downstream gene expression.