Rao et al. 2004. Mol Microbiol. Use of proteomics to identify novel virulence determinants that are required for Edwardsiella tarda pathogenesis
Instructions
Answer each of the 16 questions.
Answers should not be more than 2-3 sentences for each question.
Rao et al. 2004. Mol Microbiol. Use of proteomics to identify novel virulence determinants that are required for Edwardsiella tarda pathogenesis
https://onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2958.2004.04123.x
1. In two or fewer sentences, what was the main objective of this study?
2. In the study the authors looked at different mutants of E. tarda. What are HAMs and SAMs? What was the experimental model used to give these strains those attributions?
3. The authors began by analyzing the secreted proteins of the different strains. What is the assay presented in Fig. 3. What is the difference between panels A-C and D-F? What is the significance of the labeled spots?
4. At the time, the E. tarda genome had not been sequenced. Â How did the authors use the sequences of identified proteins to obtain the DNA sequence of the gene cluster encoding them?
5. As it turns out the Evp gene cluster encodes what would later come to be known as the type VI secretion system (T6SS). How did the authors verify that this system was important for pathogenesis?
Pukatzki et al. 2006 PNAS. Identification of a conserved bacterial protein secretion system in Vibrio cholerae using the Dictyostelium host model system
https://www.pnas.org/content/103/5/1528
6. In two or fewer sentences, what was the main objective of this study?
7. The authors use an unusual model system to measure bacterial virulence. Briefly describe this system? Name two other model systems that they could they have used and give a reason for each why the authors might have chosen not to use them.
8. The authors perform a mutagenesis screen. What is the wild type phenotype? What is the desired mutant phenotype?
9. From their screen, the authors identified several mutants in a particular gene cluster that resulted in reduced virulence. How did the authors go from a list of genes to a hypothesis about their function?
10. In Fig. 3a and 3b, the authors are measuring protein secretion. How is protein secretion being measured in 3A? In 3B? What is "bla" and why is it included in the figure?
11. In Fig. 4, what is being measured? Why do you think the authors included this experiment (i.e. what does it demonstrate that had not been demonstrated in prior figures)?
Hood et al. 2010. Cell Host Microbe. A Type VI Secretion System of Pseudomonas aeruginosa Targets a Toxin to Bacteria
https://www.cell.com/cell-host-microbe/fulltext/S1931-3128(09)00417-X
12. What is the main "unknown" regarding the type 6 secretion system that the authors are seeking to address in this study?
13. The authors began the study by identifying the secreted proteins of P. aeruginosa. Compare the process used in this paper to the steps taken by Rao et al. Give at least 2 similarities and 2 differences.
14. How do the authors confirm that the secreted proteins they identified are secreted by the T6SS?
15. Of the three secreted proteins identified, how did the authors confirm that they are toxic to eukaryotic cells? To prokaryotic Cells?
16. The authors conclude that inter-bacterial toxin delivery only works on solid media. How did they demonstrate this? Why do you think this is?
