CHARACTERIZING A NOVEL EFFECTOR PROTEIN OF EDWARDSIELLA TARDA (E. TARDA): THIOREDOXINLIKE PROTEIN (TRX3)

Abstract

Edwardsiella tarda (E. tarda) is a gram-negative bacteria which infects fish, birds and humans. It causes a great loss to the fishing industry every year. E. tarda exhibits its virulence by secreting its effector proteins into the host cell. Recent transcriptomic and bioinformatic analysis have identified novel effector proteins of E. tarda. One of the effectors, ETAE_2186, is identified as a Thioredoxin-Like Protein (TRX3). We have characterized the structure of TRX3 and elucidated substantial differences in the active site “CPVC” as compared to other TRXs. In addition, based on our cellular and biochemical assays, we have characterized TRX3 as a redox-inactive protein, which can inhibit NF-κB translocation in the host. Inhibition of NF-κB translocation is known to further downregulate the anti-inflammatory genes. Finally, we suggest a model to describe TRX3 role in NF-κB inhibition pathway during E. tarda pathogenesis.