Difference between revisions of "Part:BBa K2967017"

 
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<partinfo>BBa_K2967017 short</partinfo>
 
<partinfo>BBa_K2967017 short</partinfo>
  
In order to see whether the nitric oxide sensor will work when it comes to expressing a certain protein, we add the IL-10 downstream and demonstrated the western blotting to show the result. It has been proved that the expression level can be induced when adding nitric oxide.
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The promoter PyeaR is sensitive to nitrate and nitrite. When nitrate and nitrite enter E. coli, they are converted to nitric oxide. Nitric oxide binds to the repressor protein NsrR, which inactivates PyeaR to inhibit transcription of downstream genes. Then the promoter PyeaR will be activated to express the luciferase.
 +
 
 +
'''Usage and Biology'''
 +
 
 +
In order to detect the NO specifically and accurately,  we constructed a yeaR based NO sensor in pCDFDuet-1 plasmid, which also used by previous work. When NO bound to NsrR (the PyeaR’s transcription inhibitors), halting the repression and allowing the expression of lucifersase[1]. To test the NO sensors’ sensitivity and specificity, we chose luciferase as our reporter gene, because of the extremely sensitivity allows quantification in even small changes in transcription (Fig .1).
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 +
........
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'''Figure 1. Diagram for yeaR based NO sensor system in pCDFDuet-1 plasmid.''' PyeaR, a promoter which is sensitive to NO. Luciferase, reporter gene. Terminator B0010/B0012, double terminator.
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'''Characterization'''
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In order to simulate the inflammatory NO, 100 μM Sodium Nitroprusside Dihydrate (SNP) aqueous solution was used continuously release NO and the final concentration is stable at about 5.5μM, which is the same as the NO concentration in IBD patients [2]. We used 100 μM SNP solutions for NO sensor sensitivity testing.
 +
 
 +
For the NO sensor sensitivity testing, we transformed the constructed plasmid with NO sensor into E. coli BL21 competent cell. Competent cells are cultured at 37 ℃ overnight, and then diluted to OD600 = 0.4. And then, culture bacteria at 37 ℃ for 1.5 hours, the appropriate concentration of inducer SNP aqueous solution were added. After 2 hours of SNP induction, we detected the expression of the luciferase by Luciferase assay (from Beyotime RG005). The Luminescence data indicated that the NO released by the SNP aqueous solution can effectively activate the expression of the reporter gene. (Fig. 2)
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 +
......
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'''Figure 2. The response to NO of Pyear-luc in BL21 competent cell.''' Histogram of Luminescence(RLU): The luminescence signal can be detected from empty vector and Pyear-luc vector under either SNP induction or not.  
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Afterwards, we also transformed the PyeaR based NO sensor in our chassis, ''E. coli Nissle 1917 (EcN)''. The results were consistent with our expectation which confirmed the precise colonization of the engineered EcN in the inflammatory region. (Fig. 3)
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 +
.......
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'''Figure 3. The response to NO of Pyear-luc in E. coli Nissle 1917 .''' Histogram of
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Luminescence(RLU): The luminescence signal can be detected from empty vector and Pyear-luc vector under either SNP induction or not.
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'''reference'''
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<br />
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----fir
  
 
<!-- Add more about the biology of this part here
 
<!-- Add more about the biology of this part here
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<span class='h3bb'>Sequence and Features</span>
 
<span class='h3bb'>Sequence and Features</span>
 
<partinfo>BBa_K2967017 SequenceAndFeatures</partinfo>
 
<partinfo>BBa_K2967017 SequenceAndFeatures</partinfo>

Revision as of 14:45, 7 October 2019


Nitrate reporter: PyeaR - Luc composite

The promoter PyeaR is sensitive to nitrate and nitrite. When nitrate and nitrite enter E. coli, they are converted to nitric oxide. Nitric oxide binds to the repressor protein NsrR, which inactivates PyeaR to inhibit transcription of downstream genes. Then the promoter PyeaR will be activated to express the luciferase.

Usage and Biology

In order to detect the NO specifically and accurately, we constructed a yeaR based NO sensor in pCDFDuet-1 plasmid, which also used by previous work. When NO bound to NsrR (the PyeaR’s transcription inhibitors), halting the repression and allowing the expression of lucifersase[1]. To test the NO sensors’ sensitivity and specificity, we chose luciferase as our reporter gene, because of the extremely sensitivity allows quantification in even small changes in transcription (Fig .1).

........

Figure 1. Diagram for yeaR based NO sensor system in pCDFDuet-1 plasmid. PyeaR, a promoter which is sensitive to NO. Luciferase, reporter gene. Terminator B0010/B0012, double terminator.

Characterization

In order to simulate the inflammatory NO, 100 μM Sodium Nitroprusside Dihydrate (SNP) aqueous solution was used continuously release NO and the final concentration is stable at about 5.5μM, which is the same as the NO concentration in IBD patients [2]. We used 100 μM SNP solutions for NO sensor sensitivity testing.

For the NO sensor sensitivity testing, we transformed the constructed plasmid with NO sensor into E. coli BL21 competent cell. Competent cells are cultured at 37 ℃ overnight, and then diluted to OD600 = 0.4. And then, culture bacteria at 37 ℃ for 1.5 hours, the appropriate concentration of inducer SNP aqueous solution were added. After 2 hours of SNP induction, we detected the expression of the luciferase by Luciferase assay (from Beyotime RG005). The Luminescence data indicated that the NO released by the SNP aqueous solution can effectively activate the expression of the reporter gene. (Fig. 2)

......

Figure 2. The response to NO of Pyear-luc in BL21 competent cell. Histogram of Luminescence(RLU): The luminescence signal can be detected from empty vector and Pyear-luc vector under either SNP induction or not.

Afterwards, we also transformed the PyeaR based NO sensor in our chassis, E. coli Nissle 1917 (EcN). The results were consistent with our expectation which confirmed the precise colonization of the engineered EcN in the inflammatory region. (Fig. 3)

.......

Figure 3. The response to NO of Pyear-luc in E. coli Nissle 1917 . Histogram of

Luminescence(RLU): The luminescence signal can be detected from empty vector and Pyear-luc vector under either SNP induction or not.

reference


fir


Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    COMPATIBLE WITH RFC[21]
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal NgoMIV site found at 193
    Illegal NgoMIV site found at 1537
    Illegal NgoMIV site found at 1558
    Illegal AgeI site found at 1261
  • 1000
    INCOMPATIBLE WITH RFC[1000]
    Illegal SapI.rc site found at 1443