Composite

Part:BBa_K3420005

Designed by: JI ZhangCheng   Group: iGEM20_iBowu-China   (2020-10-24)
Revision as of 05:32, 25 October 2020 by Lucasji (Talk | contribs)


T7-ferritin-inka-Pak4cat-SV40 (poly A)

T7 promoter is a very specific promoter that is transcribed only by specific T7 RNA polymerase. The ferritin protein has been conjugated with iron, it functions as a novel hyperthermia material. The inka-Pak4cat would allow a higher conjugation of ferritin protein. Here we choose to use SV40 (poly-A) terminator as a DNA sequence with transcription termination effect.

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
    COMPATIBLE WITH RFC[25]
  • 1000
    INCOMPATIBLE WITH RFC[1000]
    Illegal BsaI.rc site found at 1527
    Illegal SapI site found at 949


1. Ft-PAK4 protein crystals grow inside mammalian cells

The Previous study has identified Inka1 as a potent inhibitor of PAK4, which contains two copies of the kinase inhibitory domain and these small regions of themselves can support PAK4cat crystal formation in cells [2]. When inka-box complexes with PAK4cat, conformational changes cause the complex to spontaneously crystallize, producing long rod-shaped crystals[1]

We generated the iron storing construct driven by promoter T7 (BBa_I712074) by fusing ferritin to the N-terminal inkabox portion of the inkabox-PAK4cat(BBa_K3420001) plasmid, which we call Ft-PAK4(BBa_K3420003). HEK293 cells, human embryonic kidney cells 293, a specific cell line originally derived from human embryonic kidney cells grown in tissue culture, are commonly used in cell biology research, because of their reliable growth and propensity for transfection. HEK293T cells derived from the HEK293 cell line expressing a mutant version of the SV40(BBa_K2796012) large T antigen. Due to they can continue to express the SV40 antigen, the cells are often used in transfection experiments with high transfection efficiency. According to Baskaran et al., HEK293T cells transfected with the control inka-PAK4 plasmid grow with a single needle-like crystal. In our experiment, we can observe that Ft-PAK4 protein expression usually begins in 24 hours after transfection, but this only happens if a small amount of the control inka-PAK4 plasmid co-transfected, and their growth lasts around 48 to 72 hours.

To make the crystals more easily visible, we also structured the Wt-PAK4 construct, which replaces ferritin with green fluorescence protein (GFP)( BBa_K3183011). With the same results, the first crystals appeared within 24 hours after transfection and continued to grow up to 72 hours after transfection. We observed that intracellular crystals were morphologically different, that is, the Ft-PAK4 crystals grew slower and shorter but thicker than Wt-PAK4 crystals.

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