P36956

SREBP-1 also known as SREBF1 is a basic helix-loop-helix-leucine zipper (bHLH-Zip) transcription factor that binds to the sterol regulatory element-1 (SRE1). SREBP-1 plays a crucial role in lipid metabolism by regulating the expression of genes involved in cholesterol and fatty acid synthesis. SREBP-1 is primarily located in the endoplasmic reticulum and the nuclear envelope, where SREBP-1 exists as a precursor form. Upon sterol depletion, SREBP-1 undergoes proteolytic cleavage, releasing a soluble fragment that translocates to the nucleus to activate transcription of target genes, thereby enhancing the uptake of low-density lipoprotein (LDL) and promoting lipid biosynthesis. The regulation of SREBP-1 is vital for maintaining cellular lipid homeostasis, as excessive cholesterol accumulation can lead to various metabolic disorders.