Difference between revisions of "Part:BBa K2285020"

Latest revision as of 08:44, 1 November 2017

J23119+Target3

This part is just the sequence of our improved Target of Star3 system. Downstream reporter genes are not included so any CDS to be controled can be added just after the Target3.

Usage and Biology

The usage of STAR3 is the same as STAR1. Check out more information about STAR1 BBa_K1893013 here.

Figure 1. The STAR construct. In the absence of antisense, sense target RNA will form a stem-loop structure, functioning as a terminator and stop the following transcription. When antisense RNA, a mRNA fragment which is the antisense of part of the target RNA, is transcribed, the terminator structure will be disrupted and switch on the inhibited transcription.

A large variety of chromoproteins can be added at the position functional gene. Here we used amilGFP, amilCP, eforRed, cjBlue four chromoproteins in our detection system but actually there are many others you can choose. To response to change of outer environment, what we need to do is just choosing the right promoter on the upstream of Antisense 1 or 3.

Charaterization

To characterize the STAR3 (also STAR1)system, we constructed the circuit below in one plasmid.

Figure2. Target3-sfGFP & Antisense3 construct. Both Target3 and Antisense3 are on the downstream of constitutive promoter J23119 and two circuits are built in plasmid pET-Duet1.

Figure 3. Characterization of STARs system over time. (A)(B) Experiments were performed in E. coli DH5α strain cultured at 37°C. Normalised endpoint fluorescence in the absence or presence of Antisense molecules. We used the dual-expression plasmid pET-Duet1 and pCDF-Duet1 for characterisation experiments involving STARs. For the absence of Antisense, the plasmid did not include Antisense circuit. Normalised fluorescence was calculated by dividing fluorescent signal by the O.D.600 value of the culture. Background was determined by the use of DH5α cells with only plasmid backbone transformed.

Figure 4. Characterization of STARs system at 600 min. (C)(D) Normalised endpoint fluorescence (600 minutes) for cell lines in the absence or presence of STAR molecules. Error bars represent standard deviation from 3 technical repeats.

Sequence and Features