Programmable polyproteams built using twin peptide superglues

Significance Many biological events depend on proteins working together as a team. Here we establish how to program team formation, covalently linking protein modules step by step. We split a domain from Streptococcus pneumoniae to form a peptide and protein pair, SnoopTag and SnoopCatcher, which form an isopeptide bond when mixed together. SnoopTag/SnoopCatcher reacted with each other but not with an alternative peptide/protein pair, SpyTag/SpyCatcher. We formed polyprotein chains by alternating SpyTag reaction with SnoopTag reaction. Cellular signaling often relies on integrated activation of different receptors, so we built polyprotein teams to stimulate Death Receptor and Growth Factor receptors, finding an optimal combination for cell-death induction in cancer cells. Programmable “polyproteams” provide a simple route to investigate or harness biological teamwork.