Membrane-bound transcription factor site-2 protease

Membrane-bound transcription factor site-2 protease, also known as S2P endopeptidase or site-2 protease (S2P), is an enzyme () encoded by the gene which liberates the N-terminal fragment of sterol regulatory element-binding protein (SREBP) transcription factors from membranes. S2P cleaves the transmembrane domain of SREPB, making it a member of the class of intramembrane proteases.
S2P catalyses the following chemical reaction
This enzyme belongs to the peptidase family M50.