Structure, function, and evolution of Gga -AvBD11, the archetype of the structural avian-double-β-defensin family
Résumé
Significance The 3-dimensional structure of Gga -AvBD11 ( Gallus gallus avian β-defensin 11) is characterized by 2 packed β-defensin domains. This makes Gga -AvBD11 the type member of a structural family dubbed here avian-double-β-defensin (Av-DBD). Its high sequence conservation among bird species suggests essential roles in the avian egg. Our results present Gga -AvBD11 as an effector of innate immunity with a broad spectrum of activities against bacterial pathogens, Eimeria parasites, and avian influenza virus. In addition, it seems to modulate cell viability, proliferation, and invasiveness. Thus, Gga -AvBD11 is likely to assist in the proper development and defense of the avian embryo. Antibacterial, antiparasitic, and antiinvasive activities are mainly mediated by its N-terminal domain. Strikingly, antiviral activity requires the full-length protein at cytotoxic concentrations.