Difference between revisions of "Part:BBa K3447133"

Revision as of 10:04, 27 October 2020

light-on induced system

This part can turn off the expression of the sfGFP gene when blue light irradiation.

Usage and Biology

YF1 is the kinase for FixJ in the blue light system. Without blue light irradiation, YF1 phosphorylates FixJ, activating the downstream expression after promoter P_FixK2. Once the blue light is on, the FixJ cannot be phosphorylated, shutting down the downstream gene expression.

Characterization

Fig. 1 Pathway of Blue Light-on System. (A) without blue light; (B) with blue light.

To enrich the blue-light sensing system, repressor pair CI-P_lambda were introduced in our project to achieve the goal of blue light-on switch system (click to Jilin_China 2020 Improvement). Therefore, in our blue light-on system, when blue light is on, P_FixK2 is blocked and P_lambda can turn on the expression of sfGFP (Fig. 1A). Without blue light, CI functions normally thereby inhibiting the expression of downstream sfGFP (Fig. 1B).
Based on the experiments above, to verify the function of blue light-on system, two control groups with mock were set to proof the activation of the blue light on our bacteria. As is shown in Fig. 2, compared with the construct without blue light, our blue light-off system would constantly activate the fluorescent expression with blue light induced.

Fig. 2 Blue Light-on system can regulate the downstream gene via switch of light. (A) The emission intensity at 528 nm was measured at the excitation wavelength of 485 nm. After that, measure these values at the indicated time. (B) E. coli DH5α with blue light-on system. (a) 18-hour incubation without blue light; (b) 18-hour incubation with blue light.

Design

Design Notes

We added some synonymous mutations to avoid part rules.

Source

We found this sequence data in GenBank.

References

Sequence and Features