Composite

Part:BBa_K4414026

Designed by: Shiyin Jin   Group: iGEM22_NUDT_CHINA   (2022-09-22)
Revision as of 15:45, 8 October 2022 by Jinshiyin (Talk | contribs)


LBD-GGGGGSG-tetR

This composite part consists of an N-terminal NR3C1 LBD(BBa_K4414000) domain and a C-terminal tetR(BBa_K4414009) domain fused with a GGGGGSG linker. It is designed to sense glucocorticoids and activates the transcription of the reporter gene.


Usage and Biology

As a glucocorticoid sensor, this part is designed to enter the nucleus upon glucocorticoid stimulation and bind to the TCE promoter to activate downstream transcription. This part consists of a tetR DNA binding domain, which binds to the TCE promoter (BBa_K4016011) consisting of seven direct 19-bp tet operator sequence (tetO) repeats. The NR3C1 LBD domain on the N terminal is the ligand�binding domain of the glucocorticoid receptor(GR). This LBD domain can translocate the fusion protein into the nucleus upon glucocorticoid stimulation. It also has a transactivating domain 2 (τ2) and an activation function domain 2 (AF2) which activates downstream gene expression.[1]

Figure1. Schematic figure of BBa_K4414026 and BBa_K4414041

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
    COMPATIBLE WITH RFC[1000]



Method

HEK-293T cells were co-transfected with plasmids encoding both BBa_K4414026 and TCE-SEAP(BBa_K4414041). Cells were treated with 10, 50, or 100 nM Glucocorticoids 6 h post-transfection. Cells without glucocorticoid treatment were used as control. Culture medium was collected at 24 h or 48 h post glucocorticoids treatment. SEAP activity was measured according to a published protocol. [2]


Result

Figure 2 Result of SEAP test. The SEAP activity was calculated at 24h and 48h after transfection.

The cells showed a nearly 40% decrease in SEAP activity after 24h blue light exposure, compared with the group exposed to dark. And after 48h, the SEAP activity in blue light group was reduce to 0. This can validate PixD and PixE’s interaction.



Reference

[1] Dine E, Gil AA, Uribe G, Brangwynne CP, Toettcher JE. Protein Phase Separation Provides Long-Term Memory of Transient Spatial Stimuli. Cell Syst. 2018 Jun 27;6(6):655-663.e5. doi: 10.1016/j.cels.2018.05.002. Epub 2018 May 30. PMID: 29859829; PMCID: PMC6023

[2] Yuan H, Bauer CE. PixE promotes dark oligomerization of the BLUF photoreceptor PixD. Proc Natl Acad Sci U S A. 2008 Aug 19;105(33):11715-9. doi: 10.1073/pnas.0802149105. Epub 2008 Aug 11. PMID: 18695243; PMCID: PMC2575306.

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