mouse monoclonal IgG1; SREBP-1 Antibody (2A4) is an IgG1 κ mouse monoclonal SREBP-1 antibody (also designated SREBP-1 antibody or SREBF1 antibody) that detects SREBP-1 of mouse, rat and human origin by WB, IP, IF and IHC(P). SREBP-1 Antibody (2A4) is available as both conjugated and non-conjugated anti-SREBP-1 antibody forms. The low density lipoprotein (LDL) receptor mediates the endocytic uptake of cholesterol-carrying lipoproteins, thereby controlling cholesterol levels in cells and plasma. Transcription of the LDL receptor gene is controlled by a ten base pair sequence in the 5' flanking region, designated sterol regulatory element 1 (SRE-1). When cellular sterol stores are depleted, the element is activated, the gene is transcribed and the cellular uptake of LDL increases. A set of SRE-binding proteins (SREBPs) have been identified, including two basic helix-loop-helix leuicine zipper (bHLH-Zip) transcription factors, designated SREBP-1 and SREBP-2. SREBP-1 (also designated ADD1, for adipocyte determination and differentiation factor) is synthesized as a precursor that is attached to the nuclear envelope and endoplasmic reticulum. In sterol-depleted cells, the membrane-bound precursor is cleaved to generate a soluble NH2-terminal fragment that translocates to the nucleus to activate transcription. Sterols inhibit the cleavage of SREBP-1.