Furin-like Protease

A furin-like protease is a recursor (prehormone, preprotein) conveitase (PC). 

Figure 5 Proteolytic processing and signaling of the Notch receptor. In the ER, Notch is cleaved at SI by a furin-like protease to produce a stable heterodimeric receptor that is trafficked to the cell surface. Interaction with ligands such as the proteins Delta and Jagged triggers a shedding of the ectodomain by membrane-tethered metalloprotease-mediated cleavage at S2. The remnant then is cleaved at least twice, at the S3 and S4 sites, to release the Notch counterpart of Ap (Np) and the intracellular domain (NICD). The latter translocates to the nucleus where it interacts with transcription factors to influence gene expression relevant to cell differentiation.

All human metzincins are secreted as proenzymes. Astacins and adamalysins are mostly activated by calcium-ion-dependent serine proteases pro-protein convertases) that meet up with their substrates in trans-Golgi and secretory vacuoles. These proenzymes are known as furin-like convertases because of their homology to a serine protease called furin and a bacterial endoprotease called subtilisin. The furin-like enzymes require calcium ions to maintain structural stability whereas other serine proteases, represented by trypsin and chymotrypsin, do not. The furin-like pro-protein convertases autocleave their own N-terminal domain propeptide (self-activate) during secretion and then convert the N-terminal domains of co-secreted metzincins. Activation cascades also occur among the... 

Furin, also known as paired basic amino-acid-cleaving enzyme (PACE), is a membrane bound subtilisin-like serine protease of the irons Golgi compartment. It is ubiquitously expressed and mediates processing of many protein precursors at Arg-X-Lys/Arg-Arg sites. 

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