Proprotein convertase 2 (PC2) also known as prohormone convertase 2 or neuroendocrine convertase 2 (NEC2) is a serine protease

Serine protease

Serine proteases are enzymes that cleave peptide bonds in proteins, in which serine serves as the nucleophilic amino acid at the active site.They are found ubiquitously in both eukaryotes and prokaryotes...

 and proprotein convertase PC2, like proprotein convertase 1

Proprotein convertase 1

Proprotein convertase 1, also known as prohormone convertase, prohormone convertase 3, or neuroendocrine convertase 1 and often abbreviated as PC1/3 is an enzyme that in humans is encoded by the PCSK1 gene...

 (PC1), is an enzyme responsible for the first step in the maturation of many neuroendocrine peptides from their precursors, such as the conversion of proinsulin to insulin

Insulin

Insulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....

 intermediates. To generate the bioactive form of insulin (and many other peptides), a second step involving the removal of C-terminal basic residues is required; this step is mediated by carboxypeptidases E and/or D. PC2 plays only a minor role in the first step of insulin biosynthesis, but a greater role in the first step of glucagon

Glucagon

Glucagon, a hormone secreted by the pancreas, raises blood glucose levels. Its effect is opposite that of insulin, which lowers blood glucose levels. The pancreas releases glucagon when blood sugar levels fall too low. Glucagon causes the liver to convert stored glycogen into glucose, which is...

 biosynthesis compared to PC1. PC2 binds to the neuroendocrine protein named 7B2, and if this protein is not present, proPC2 cannot become enzymatically active. 7B2 also inhibits PC2 activity until the 7B2 is cleaved into smaller inactive forms. Thus, 7B2 is both an activator and an inhibitor of PC2.

In humans, proprotein convertase 2 is encoded by the PCSK2 gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

. It is related to the bacterial enzyme subtilisin, and altogether there are 9 different subtilisin-like genes in mammals: furin

Furin

Furin is a protein that in humans is encoded by the FURIN gene. It was named furin because it was in the upstream region of an oncogene known as FES. The gene was known as FUR and therefore the protein was named furin...

, PACE4

PCSK6

Proprotein convertase subtilisin/kexin type 6 is an enzyme that in humans is encoded by the PCSK6 gene.-Further reading:...

, PC4

PCSK4

Proprotein convertase subtilisin/kexin type 4 is an enzyme that in humans is encoded by the PCSK4 gene.-Further reading:...

, PC5/6

PCSK5

Proprotein convertase subtilisin/kexin type 5 is an enzyme that in humans is encoded by the PCSK5 gene.-Further reading:...

, PC7/8

PCSK7

Proprotein convertase subtilisin/kexin type 7 is an enzyme that in humans is encoded by the PCSK7 gene.-Further reading:...

, PCSK9

PCSK9

Proprotein convertase subtilisin/kexin type 9, also known as PCSK9, is an enzyme which in humans is encoded by the PCSK9 gene with orthologs found across many species.- Function :...

, and SKI1/S1P.