Figure 2. Sema3C activity is regulated by proteolytic cleavage.

Sema3C is synthesized as a secreted full-length molecule, with a basic-charged C'-tail putatively tethering it to the cell surface and interacting with the co-receptor Nrp1. MMPs have been found to remove this C'-sequence, enhancing Sema3C extracellular diffusion. On the other hand, furin-like convertases are found to release the sema domain from the rest of the molecule; this ablates the inhibitory activity for EC and vessels, but allegedly preserves other functions, such as tumour promotion.