Sterol Regulatory Element-Binding Protein 1 (SREBF1) Pig Recombinant Protein

Function: Transcriptional activator required for lipid homeostasis. Regulates transcription of the LDL receptor gene as well as the fatty acid and to a lesser degree the cholesterol synthesis pathway. Binds to the sterol regulatory element 1 (SRE-1) (5'-ATCACCCCAC-3'). Has dual sequence specificity binding to both an E-box motif (5'-ATCACGTGA-3') and to SRE-1 (5'-ATCACCCCAC-3')

By similarity.

Subunit structure: Forms a tight complex with SCAP in the ER membrane. Efficient DNA binding of the soluble transcription factor fragment requires dimerization with another bHLH protein. Interacts with LMNA

By similarity.

Subcellular location: Endoplasmic reticulum membrane; Multi-pass membrane protein

By similarity. Golgi apparatus membrane; Multi-pass membrane protein

By similarity. Cytoplasmic vesicle › COPII-coated vesicle membrane; Multi-pass membrane protein

By similarity. Note: Moves from the endoplasmic reticulum to the Golgi in the absence of sterols.Processed sterol regulatory element-binding protein 1: Nucleus

By similarity.

Post-translational modification: At low cholesterol the SCAP/SREBP complex is recruited into COPII vesicles for export from the ER. In the Golgi complex SREBPs are cleaved sequentially by site-1 and site-2 protease. The first cleavage by site-1 protease occurs within the luminal loop, the second cleavage by site-2 protease occurs within the first transmembrane domain and releases the transcription factor from the Golgi membrane. Apoptosis triggers cleavage by the cysteine proteases caspase-3 and caspase-7

By similarity.Phosphorylated by AMPK, leading to suppress protein processing and nuclear translocation, and repress target gene expression. Phosphorylation at Ser-403 by SIK1 represses activity possibly by inhibiting DNA-binding

By similarity.

Sequence similarities: Belongs to the SREBP family.Contains 1 bHLH (basic helix-loop-helix) domain.