Human SREBP2 Antibody

SREBP2 (Sterol Regulatory Element-Binding Protein 2; also bHLHD2 and SREBF2) is a 120-125 kDa member of the SREBP family of proteins. It is ubiquitously expressed and found in the intracellular membrane fraction of cells. SREBP2 is a transcriptional factor initially embedded in the ER as an inactive precursor associated with SCAP. When necessary, SCAP mediates SREBP2 transfer to the Golgi, where two resident proteases remove the N-terminus from SREBP2, and the N-terminus is transported into the nucleus. Here, SREBP2 acts as a transcription factor, activating the LDLR and cholesterol synthesis genes. The human SREBP2 precursor is an 1141 amino acid (aa) two transmembrane protein whose N- and C-termini are cytoplasmic. The two cytoplasmic domains span aa 1-479 and 555-1141, respectively. Proteolytic cleavage between Leu484-Cys485 generates the 64-66 kDa SREBP2 transcription factor. This fragment contains a bHLH DNA binding domain (aa 330-380) and one Leu zipper region (aa 381-401). Homodimerization of SREBP2 is necessary for nuclear translocation. There is one potential isoform that shows a deletion of aa 274-276 coupled to a 96 aa substitution for aa 580-1141. A second isoform (known in rodent) shows a premature truncation after Val463 and runs at 55 kDa in SDS-PAGE. Over aa 242-450, human SREBP2 shares 97% aa identity with mouse SREBP2.