Rabbit polyclonal antibody to SREBP~1 (phospho~S439) polyclonal antibody

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. 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.