Investigating the antimicrobial properties of X-Tox proteins

Antimicrobial proteins and peptides (AMPs) are crucial components of innate immune systems in multicellular organisms, serving as effectors against pathogen infections. Insect defensins and their homologs, including X-tox, represent a diverse AMP family, most of which exhibit activity against bacteria or fungi. These peptides share a conserved three-dimensional αβ fold stabilized by three disulfide bonds characteristic of defensins. In Manduca sexta, four X-tox variants have been identified, arising not from gene duplication but through exon duplication, sequence divergence, and alternative splicing. The M. sexta 5-tox gene comprises six exons, with exons 2 through 6 each encoding a tox domain. This project aims to investigate whether specific isoforms of the X-tox AMP can gain functionality and to determine if different isoforms can act synergistically to enhance the insect’s immune response.