Membrane Bound Transcription Factor Peptidase Site 1 (MBTPS1)

Membrane-bound transcription factor peptidase, site 1 has a central role in the regulation of lipid metabolism in cells. It is a sterol-regulated subtilisin-like serine protease that cleaves ER membrane-bound sterol regulatory element-binding proteins (SREBPs), a reaction that initiates the two-step proteolytic process by which transcriptionally active fragments of SREBPs are released from the membrane for translocation to the nucleus. The gene product is an integral membrane ER protein, with the bulk located in the ER lumen. It is synthesized as an inactive preproprotein that is self-activated by an intramolecular cleavage that generates the mature protein.The propeptide is autocatalytically removed through an intramolecular cleavage after Leu-186. Further cleavage generates 14, 10, and 8kDa intermediates.