Induction of caspase-8 in human cells by the extracellular administration of peptides containing a C-terminal SLV sequence

Summary Extracellular administration of a membrane permeable model peptide containing the tripeptide sequence, SLV, at the C-terminus to human endothelial and kidney cells resulted in an induction of caspase-8 (FLICE), the apical enzyme of the apoptosis caseade. The unmodified or N-terminally SLV-tagged peptide had no effect, thereby eliminating an unspecific induction of apoptosis as the cause of the caspase activity observed. Drastic alterations of primary structure and structure forming properties of the carrier peptide did not significantly influence the caspase-8 inducing activity of the C-terminal SLV-tag, supporting previous findings that translocation into the cell interior is a more general ability of peptides.