Hymenopterans represent one of the most abundant groups of venomous organisms but remain little explored due to the difficult access to their venom. The development of proteo-transcriptomic allowed us to explore diversity of their toxins offering interesting perspectives to identify new biological active peptides. This study focuses on U 9 function, a linear, amphiphilic and polycationic peptide isolated from ant Tetramorium bicarinatum venom. It shares physicochemical properties with M-Tb1a, exhibiting cytotoxic effects through membrane permeabilization. In the present study, we conducted a comparative functional investigation of U 9 and M-Tb1a and explored the mechanisms underlying their cytotoxicity against insect cells. After showing that both peptides induced the formation of pores in cell membrane, we demonstrated that U 9 induced mitochondrial damage and, at high concentrations, localized into cells and induced caspase activation. This functional investigation highlighted an original mechanism of U 9 questioning on potential valorization and endogen activity in T. bicarinatum venom.
Toxicology; Entomology; Biochemistry