MREwt promoter

Usage and Biology

The MRE-sites containing promoter enables the metal-dependent expression of a downstream positioned reporter gene via the metal ion-dependent transcription factor MTF-1 (K5317007) for cell-based metal detection.

The varying Metal Responsive Elements (MREs) upstream of the eukaryotic metallothionein (MT) gene were discovered in the early 80s (Carter et al., 1984; Stuart et al., 1985). All MREs a-d carry core consensus sites (TGCRCNC) to which the primary MRE-binding transcription factor MTF-1 can bind after binding to heavy metal ions and translocating into the nucleus (Wang et al., 2004). Physiologically, this leads to the expression of metallothionein, a protein capable of binding metals such as zinc, cadmium, copper, and others for metal homeostasis and detoxification (Cousins, 1983). The arrangement of the MREs in our promoter construct was inspired by publications from Glanville et al. (1981) and Searle et al. (1985), maintaining the order of MREs from the physiological murine MT promoter.

Cloning

Theoretical Part Design

The MREwt promoter was synthesized, and the MREa-d motifs were positioned similarly to the physiological murine promoter upstream of the metallothionein gene.

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]

Characterization

The promoter was analyzed by composing a gene cassette where it is placed upstream of the reporter gene EGFP to assess the promoter's functionality and metal-dependent efficiency based on the fluorescent signal. Please visit the K5317008 registry entry to view the results.

References

Carter, A. D., Felber, B. K., Walling, M. J., Jubier, M. F., Schmidt, C. J., & Hamer, D. H. (1984). Duplicated heavy metal control sequences of the mouse metallothionein-I gene. Proceedings of the National Academy of Sciences of the United States of America, 81(23), 7392–7396. https://doi.org/10.1073/pnas.81.23.7392

Cousins R. J. (1983). Metallothionein--aspects related to copper and zinc metabolism. Journal of inherited metabolic disease, 6 Suppl 1, 15–21. https://doi.org/10.1007/BF01811318

Glanville, N., Durnam, D. M., & Palmiter, R. D. (1981). Structure of mouse metallothionein-I gene and its mRNA. Nature, 292(5820), 267–269. https://doi.org/10.1038/292267a0

Searle, P. F., Stuart, G. W., & Palmiter, R. D. (1985). Building a metal-responsive promoter with synthetic regulatory elements. Molecular and cellular biology, 5(6), 1480–1489. https://doi.org/10.1128/mcb.5.6.1480-1489.1985

Stuart, G. W., Searle, P. F., & Palmiter, R. D. (1985). Identification of multiple metal regulatory elements in mouse metallothionein-I promoter by assaying synthetic sequences. Nature, 317(6040), 828–831. https://doi.org/10.1038/317828a0#