In Vivo Biochemistry: Single-cell dynamics of cyclic di-GMP in E. col…

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  • Writer 최고관리자
  • 2018-01-02


[BK21 Plus Seminar]

▶Subject: In Vivo Biochemistry:  Single-cell dynamics of cyclic di-GMP in E. coli in response to zinc overload

▶Speaker: Jongchan Yeo, Ph.D. (University of California, Berkeley)
▶Date: 2:30PM/Jan. 2(Tue.)/2018
▶Place: Life Science Bldg. #207

Intracellular signaling enzymes drive critical changes in cellular physiology and gene expression, but their endogenous activities in vivo remain highly challenging to study in real-time and for individual cells. Here we show that flow cytometry can be performed in complex media to monitor single-cell population distributions and dynamics of cyclic di-GMP signaling in E. coli, which controls the bacterial colonization program. These in vivo biochemistry experiments are enabled by our second-generation RNA-based fluorescent (RBF) biosensors, which exhibit high fluorescence turn-on in response to cyclic di-GMP. Specifically, we demonstrate that intracellular levels of cyclic di-GMP are repressed with excess zinc, but not with other divalent metals. Furthermore, in both flow cytometry and fluorescence microscopy set-ups, we monitor the dynamic rise in cellular cyclic di-GMP levels upon zinc depletion and show that this response is due to de-repression of the endogenous diguanylate cyclase DgcZ. In the presence of zinc, cells exhibit enhanced cell motility and increased sensitivity to antibiotics due to inhibited biofilm formation. Taken together, these results showcase the application of RBF biosensors to visualize single-cell dynamic changes in cyclic di-GMP signaling in direct response to environmental cues such as zinc, and highlight our ability to assess whether or not observed phenotypes are related to specific signaling enzymes and pathways.

▶Inquiry: Prof. Yunje Cho (279-2288)

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