Composite

Part:BBa_K4890013

Designed by: Duoqing LIN   Group: iGEM23_Shanghai-SDG   (2023-08-14)
Revision as of 11:11, 9 October 2023 by JY Z (Talk | contribs)


UAS-Hsp70-MTF1

This part is responsible to the expression of MTF-1 gene driven by UAS in Drosophila. It consists of UAS sequence (BBa_K3281012), Hsp70 sequence (BBa_K4890004) and MTF-1 gene (BBa_K4890001). UAS and Hsp70 are derived from pUAST plasmid. Upstream activating sequence (UAS) is a cis-acting regulatory sequence. It increases the expression of a neighbouring gene when binds to GAL4. Hsp70 is a promoter that can bind to RNA polymerase and start transcription. MTF-1 gene is derived from Drosophila melanogaster. It encodes MTF-1 (metal-responsive transcription factor-1) which is a transcription factor. MTF-1 protein can be activated by heavy metals. In the cell nucleus of Drosophila cells, MTF-1 binds to MRE to recruit RNA polymerase, in turn increasing the expression of Mto/Mtn to detoxicate metals.

Sequence and Features


Assembly Compatibility:
  • 10
    INCOMPATIBLE WITH RFC[10]
    Illegal EcoRI site found at 382
    Illegal EcoRI site found at 2296
    Illegal PstI site found at 244
    Illegal PstI site found at 2054
    Illegal PstI site found at 2232
  • 12
    INCOMPATIBLE WITH RFC[12]
    Illegal EcoRI site found at 382
    Illegal EcoRI site found at 2296
    Illegal NheI site found at 509
    Illegal PstI site found at 244
    Illegal PstI site found at 2054
    Illegal PstI site found at 2232
  • 21
    INCOMPATIBLE WITH RFC[21]
    Illegal EcoRI site found at 382
    Illegal EcoRI site found at 2296
    Illegal BglII site found at 527
    Illegal BamHI site found at 479
    Illegal BamHI site found at 1468
    Illegal BamHI site found at 1864
    Illegal BamHI site found at 1891
  • 23
    INCOMPATIBLE WITH RFC[23]
    Illegal EcoRI site found at 382
    Illegal EcoRI site found at 2296
    Illegal PstI site found at 244
    Illegal PstI site found at 2054
    Illegal PstI site found at 2232
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal EcoRI site found at 382
    Illegal EcoRI site found at 2296
    Illegal PstI site found at 244
    Illegal PstI site found at 2054
    Illegal PstI site found at 2232
    Illegal NgoMIV site found at 1730
  • 1000
    COMPATIBLE WITH RFC[1000]


Results

1 Construction of pUAST-MTF-1 plasmid

We took a commercialized recombinant plasmid pUAST as template, and used restrictive endonuclease (BglII and XhoI) digestion to obtain a linearized pUAST vector. MTF-1 gene fragment was amplified from the cDNA of wildtype Drosophila melanogaster by PCR. DNA electrophoresis confirmed the length of the PCR product (2376bp). MTF-1 gene fragment was ligated with the pUAST linearized vector by T4 ligase. pUAST-MTF-1 was transformed into E. coli DH5α strain. Colony PCR and DNA electrophoresis (2376bp) was performed to confirm the positive colonies. These colonies were transferred and expanded. Plasmid extracted from the colonies was confirmed to be pUAST-MTF-1 plasmid by gene sequencing (Figure 1-2).

Figure 1 Gel electrophoresis of MTF-1

Figure 2 Gel electrophoresis of pUAST-MTF-1 plasmid
(From left to right: marker, pUAST-MTF-1, pMRE-Hid and pMRE-GFP)

2 Transient transfection of Drosophila S2 cells with pUAST-MTF-1, pMRE-Hid, and pAc-GAL4 plasmids

We cultured Drosophila S2 cells on plates for 24h, and then transiently co-transfected pUAST-MTF-1, pMRE-Hid (refer to BBa_K4890014) and pAc-GAL4 (which contains actin-GAL4) plasmids into the S2 cells. pAc-GAL4 plasmid was previous constructed by Genetic Lab, School of Life Science and Technology, Tongji University. The transfected S2 cells were notated as Drosophila UAS-MTF-1/MRE-Hid/Ac-GAL4 cells.

Drosophila UAS-MTF-1/MRE-Hid/Ac-GAL4 cells were cultured for 48h and then divided into 5 groups. The control group received no treatment, and the other 4 groups were treated with 10μM ZnCl2, 100μM ZnCl2, 10μM CdCl2, and 100μM CdCl2, respectively, for 4h.

Real-time PCR and Western Blot results confirmed that both mRNAs and proteins of MTF-1 and Hid were expressed in Drosophila UAS-MTF-1/MRE-Hid/Ac-GAL4 cells treated with 10μM and 100μM ZnCl2 or CdCl2 (Figure 3-4). The mRNA and protein levels of Hid were concentration-dependent (P<0.05). The mRNA level of MTF-1 was not changed with the addition of metal ions (P>0.05).

Figure 3 mRNA levels of MTF-1 and Hid in Drosophila UAS-MTF-1/MRE-Hid/Ac-GAL4 cells treated with different concentrations of ZnCl2 or CdCl2
(unpaired t-test: ***P<0.001, ****P<0.0001, ns: P>0.05)

Figure 4 Protein levels of MTF-1 and Hid in Drosophila UAS-MTF-1/MRE-Hid/Ac-GAL4 cells treated with different concentrations of ZnCl2 or CdCl2
(Note: MTF-1 was detected by antibody of HA tag, which was co-expressed at the N-terminal of MTF-1. Hid was detected by antibody of Myc tag, which was co-expressed at the C-terminal of Hid)

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