Daqing Jiang, PhD candidate in the Department of Biological Sciences at UW-Milwaukee, will present a talk about her research, entitled ‘Bacterial Envelope Stress Signaling on the Regulation of Type III Secretion System in Dickeya dadantii 3937’.

Bacteria are known for their incredible abilities to rapidly sense and respond to environmental changes. One of the major methods bacteria employed to increase their adaptability is through two-component signal transduction systems (TCSs). A typical TCS transduces a phosphorylation cascade from a histidine kinase to its cognate response regulator. The phosphorylated response regulator is thus capable of transcriptional and post-transcriptional regulating various target gene expressions. Phytopathogen Dickeya dadantii 3937 genome encodes a homolog of the CpxA/R TCS that was previously characterized in the Escherichia coli. E. coli Cpx signaling pathway is involved in the detection and degradation of misfolded envelope proteins. However, few studies investigate the role of Cpx signaling pathway on the pathogenesis in phytopathogens. Here, we report an envelope-localized protein complex, type III secretion system (T3SS), is subject to the regulation by CpxR. T3SS is one of the major virulence determinants that contributes to bacterial pathogenicity, it enables bacterial pathogens to deliver virulence factors directly into the host cells. We showed a negative role of CpxR on T3SS expression and further investigated the cell’s decision on different signaling cascades under T3SS inducing conditions.

The presentation will begin at 4:00 PM via Microsoft Teams, preceded by an informal Q&A from 3:45 – 4:00 PM.