Part:BBa_K4414021

LBD-EGFP

This composite part consists of an C-Terminal EGFP (Part:BBa_K1123017) and a N-Terminal GR LBD (Part:BBa_K4414000) domain. It is designed to sense glucocorticoids and locate glucocorticoid receptor (GR) in cells.

Usage and Biology

We constructed a plasmid to link LBD with the fluorescent protein EGFP to verify the function of LBD. The EGFP on the C-Terminal locates glucocorticoid reporter (GR). The GR LBD domain on the N-Terminal is a 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 trans-activating domain 2 (τ2) and an activation function domain 2 (AF2) which activates downstream gene expression(Weikum et al., 2017).

Figure 1.Schematic figure of BBa_K4414021

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]

Fuctional test

Method

To test the ability of this part to respond to glucocorticoids, HEK-293T cells were co-transfected with plasmids encoding BBa_K4414021. Cells were treated with 100 nM Glucocorticoids 6 h post-transfection. Cells without glucocorticoid treatment were used as control. The fluorescence intensity of cells was observed 24 h after posting glucocorticoids treatment.

Result

Fluorescence images are shown below, which indicates that glucocorticoids can bind to LBD and enter the nucleus. This provides a basic direction of thinking for our experiments.

Figure 2.The picture on the left is Bright-field cell diagram, the picture in the middle is fluorescence diagram, and the picture on the right is merge diagram.

Reference

1. Weikum, E. R., Knuesel, M. T., Ortlund, E. A., & Yamamoto, K. R. (2017). Glucocorticoid receptor control of transcription: precision and plasticity via allostery. Nature reviews. Molecular cell biology, 18(3), 159–174. https://doi.org/10.1038/nrm.2016.152