The Peptide Venom Composition of the Fierce Stinging Ant Tetraponera aethiops (Formicidae: Pseudomyrmecinae)

Valentine Barassé (1) , Axel Touchard (1) , Nathan Téné (1) , Maurice Tindo (2) , Martin Kenne (2) , Christophe C. Klopp (3) , Alain Dejean (4, 5) , Elsa Bonnafé (1) , Michel Treilhou (1)

1 INUC - Institut national universitaire Champollion [Albi]
2 Université de Douala
3 MIAT INRAE - Unité de Mathématiques et Informatique Appliquées de Toulouse
4 LEFE - Laboratoire Ecologie Fonctionnelle et Environnement
5 UG - Université de Guyane

In the mutualisms involving certain pseudomyrmicine ants and different myrmecophytes (i.e., plants sheltering colonies of specialized "plant-ant" species in hollow structures), the ant venom contributes to the host plant biotic defenses by inducing the rapid paralysis of defoliating insects and causing intense pain to browsing mammals. Using integrated transcriptomic and proteomic approaches, we identified the venom peptidome of the plant-ant Tetraponera aethiops (Pseudomyrmecinae). The transcriptomic analysis of its venom glands revealed that 40% of the expressed contigs encoded only seven peptide precursors related to the ant venom peptides from the A-superfamily. Among the 12 peptide masses detected by liquid chromatography-mass spectrometry (LC-MS), nine mature peptide sequences were characterized and confirmed through proteomic analysis. These venom peptides, called pseudomyrmecitoxins (PSDTX), share amino acid sequence identities with myrmeciitoxins known for their dual offensive and defensive functions on both insects and mammals. Furthermore, we demonstrated through reduction/alkylation of the crude venom that four PSDTXs were homo- and heterodimeric. Thus, we provide the first insights into the defensive venom composition of the ant genus Tetraponera indicative of a streamlined peptidome.

Mots clés: defensive venom; dimeric peptides; peptidome; Tetraponera aethiops

Domaines: Sciences du Vivant [q-bio]

Valentine Barassé, Axel Touchard, Nathan Téné, Maurice Tindo, Martin Kenne, et al.. The Peptide Venom Composition of the Fierce Stinging Ant Tetraponera aethiops (Formicidae: Pseudomyrmecinae). Toxins, 2019, 11 (12), pp.732. ⟨10.3390/toxins11120732⟩. ⟨hal-03115116⟩