PCSK1
Description
The PCSK1 (proprotein convertase subtilisin/kexin type 1) is a protein-coding gene located on chromosome 5.
PCSK1, encoding proprotein convertase 1 (PC1/3), is a human enzyme responsible for proteolytic cleavage of prohormones into their intermediate (or sometimes fully cleaved) forms. Found in neuroendocrine cells like the brain, pituitary, and adrenal glands, it typically cleaves after a pair of basic amino acid residues within prohormones but can also cleave after a single arginine. PC1/3 binds to a protein called proSAAS, which functions as its endogenous inhibitor. It is synthesized as a 99 kDa proform, quickly converted to an 87 kDa active form, which then undergoes further cleavage to a 66 kDa active form within these cells. PC1/3 plays a crucial role in the first step of insulin biosynthesis. Following its action, a carboxypeptidase removes the basic residues from the processing intermediate, producing the bioactive form of insulin. Another prohormone convertase, proprotein convertase 2, plays a smaller role in the first step of insulin biosynthesis but a larger role in glucagon biosynthesis. While the knockout of proprotein convertase 1 is not lethal in mice or humans, likely due to the presence of the second convertase, mice lacking PC1/3 activity show defects like slow growth.
PCSK1 is also known as BMIQ12, NEC1, PC1, PC1/3, PC3, SPC3.
