Primary Structure and in Vitro Antibacterial Properties of the Drosophila melanogaster Attacin C Pro-domain

Abstract

In Drosophila melanogaster, seven distinct families of antimicrobial peptides with different structures and specificities are synthesized by the fat body and released into the hemolymph during the immune response. Using microscale high performance liquid chromatography, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and Edman degradation, we have isolated and characterized from immune-challenged Drosophila two novel induced molecules, under the control of the Imd pathway, that correspond to post-translationally modified antimicrobial peptides or peptide fragments. The first molecule is a doubly glycosylated form of drosocin, an O-glycosylated peptide that kills Gram-negative organisms. The second molecule represents a truncated form of the pro-domain of the Drosophila attacin C carrying two post-translational modifications and has significant structural similarities to proline-rich antibacterial peptides including drosocin. We have synthesized this peptide and found that it is active against Gram-negative bacteria. Furthermore, this activity is potentiated when the peptide is used in combination with the Drosophila antimicrobial peptide cecropin A. The synergistic action observed between these two molecules suggests that the truncated post-translationally modified pro-domain of attacin C by itself may play an important role in the antimicrobial defense of Drosophila.

An Antiviral Role for Antimicrobial Peptides during the Arthropod Response to Alphavirus Replication

“…DptB shares the canonical furin cleavage site (RVRR) with AttA and AttB, while the AttC cleavage site differs by one amino acid (RARR). The AttC propeptide, also known as Maturated Prodomain of Attacin-C (MPAC), has been shown to have antibacterial activity, independent of the rest of the protein (53). AttC and DptB also include glycine-rich regions.…”

An antimicrobial peptide with trypanocidal activity characterized from Glossina morsitans morsitans

“…While the growth inhibitory activity of Attacin characterized from Hyalophora cecropia, eri-silkworm and Drosophila has been previously demonstrated against bacteria (Hultmark et al, 1983;Kishimoto et al, 2002;Rabel et al, 2004), its action against a eukaryotic protozoan is novel. Interestingly, the gramnegative symbiont of tsetse, Sodalis is found to be significantly more resistant to the bactericidal action of recAttacin than either E. coli or the African trypanosomes.…”

Latarcins, Antimicrobial and Cytolytic Peptides from the Venom of the Spider Lachesana tarabaevi (Zodariidae) That Exemplify Biomolecular Diversity

“…Examples of AMP precursors that are processed into mature chains of different types include precursors of cathelicidins (46), attacin C from Drosophila (47), and modular precursor proteins from the plants Macadamia integrifolia and Cucurbita maxima (48,49).…”