Membrane-bound transcription factor site-1 protease


Membrane-bound transcription factor site-1 protease, or site-1 protease for short, also known as subtilisin/kexin-isozyme 1, is an enzyme that in humans is encoded by the MBTPS1 gene. S1P cleaves the endoplasmic reticulum loop of sterol [regulatory element-binding protein] transcription factors.

Function

This gene encodes a member of the subtilisin-like proprotein convertase family, which includes proteases that process protein and peptide precursors trafficking through regulated or constitutive branches of the secretory pathway. The encoded protein undergoes an initial autocatalytic processing event in the endoplasmic reticulum to generate a heterodimer which exits the ER and sorts to the cis/medial-Golgi where a second autocatalytic event takes place and the catalytic activity is acquired. It encodes a type 1 membrane bound protease which is ubiquitously expressed and regulates cholesterol or lipid homeostasis via cleavage of substrates at non-basic residues.

Clinical significance

Mutations in this gene may be associated with lysosomal dysfunction.