Sometimes they come back: Endocytosis provides localization dynamics of a subtilase in cells committed to cell death

Proteins are synthesized in the cytoplasm of cells and delivered to their destinations with the aid of targeting signals within their amino acid sequences and through interactions with other proteins. However a number of proteins are capable of further re-localization in response to external and internal cues, thus allowing the cell to adapt to changing environmental conditions. For plant subtilisin-like proteases (subtilases), secretion of mature enzymes into the extracellular space, the apoplast, has until now been considered to be the end point of their journey. But this may not be the case, and here we present and discuss data showing that for extracellular death-promoting plant subtilases clathrin-mediated endocytosis provides a gateway to re-enter cells committed to cell death.