Adaptations of Interferon Regulatory Factor 3 with Transition from Terrestrial to Aquatic Life

Authors

• Monica Angeletti, University of Nebraska, Lincoln
• Wan-Ling Nicole Hsu, University of Nebraska, Lincoln & University of Washington, Washington
• Nashaat Majo, University of Nebraska, Lincoln
• Hideaki Moriyama, University of Nebraska, Lincoln
• Etsuko Moriyama, University of Nebraska, LincolnFollow
• Luwen Zhang, University of Nebraska, LincolnFollow

Document Type

Article

Date of this Version

2020

Citation

Scientific Reports | (2020) 10:4508 | https://doi.org/10.1038/s41598-020-61365-9

Comments

The Author(s) 2020

Abstract

Interferon regulatory factor 3 (IRF3) and IRF7 are closely related IRF members and the major factors for the induction of interferons, a key component in vertebrate innate immunity. However, there is limited knowledge regarding the evolution and adaptation of those IRFs to the environments. Two unique motifs in IRF3 and 7 were identified. One motif, GASSL, is highly conserved throughout the evolution of IRF3 and 7 and located in the signal response domain. Another motif, DPHK, is in the DNA-binding domain. The ancestral protein of IRF3 and 7 seemed to possess the DPHK motif. In the ray-finned fish lineage, while the DPHK is maintained in IRF7, the motif in IRF3 is changed to NPHK with a D → N amino acid substitution. The D → N substitution are also found in amphibian IRF3 but not in amphibian IRF7. Terrestrial animals such as reptiles and mammals predominantly use DPHK sequences in both IRF3 and 7. However, the D → N substitution in IRF3 DPHK is again found in cetaceans such as whales and dolphins as well as in marsupials. These observations suggest that the D → N substitutions in the IRF3 DPHK motif is likely to be a