Difference between revisions of "Part:BBa K1993015"

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Luciferase (Renilla reniformis)

Luciferase is a generic term for the class of oxidative enzymes that produce bioluminescence, and is distinct from a photoprotein. A variety of organisms regulate their light production using different luciferases in a variety of light-emitting reactions. So, multiple luciferases had been found and used in biological researches. We had constructed two kinds of luciferases. One of them was Renilla-luciferin 2-monooxygenase that is from Renilla reniformis [1]. Unlike other fluorescent proteins, light excitation is not needed for luciferase bioluminescence, which means minimal autofluorescence and therefore virtually background-free fluorescence[2]. In other words, since luciferase reaction is a enzymatic reaction, light is emitted when luciferase acts on the appropriate luciferin substrate. Photon emission can be detected by light sensitive apparatus such as aluminometer or modified optical microscopes. This allows observation of biological processes[3]. RLuc catalyzes the chemical reaction

Coelenterazine + O2 → coelenteramide + CO2 + hν

In the process, RLuc is oxidized, and a photon of blue light is emitted.

Figure 1 Mechanism for luciferase [4].

In biological research, luciferase is commonly used as a reporter to assess the transcriptional activity in cells that are transfected with a genetic construct containing the luciferase gene under the control of a promoter of interest[5]. But in our project, we used luciferase for another purpose: trace the cells non-invasively inside a live mouse using a sensitive charge-couple device camera.

Once we purified the gene luciferase(Figure 2), we modified our mesenchymal stem cells(MSCs) by adding such gene under the control of EF1-a, then tested inside a mouse(Figure 3). From the picture, we can clearly know the precise location of the MSCs in vivo.

Figure 2 Purification of gene Luciferase

Figure 3 Luciferase indicating the position of MSCs in vivo

References

[1] Loening, A. M.; Fenn, T. D.; Gambhir, S. S. (2007). "Crystal Structures of the Luciferase and Green Fluorescent Protein from Renilla reniformis". Journal of Molecular Biology. 374 (4): 1017–1028

[2] Williams TM, Burlein JE, Ogden S, Kricka LJ, Kant JA (Jan 1989). "Advantages of firefly luciferase as a reporter gene: application to the interleukin-2 gene promoter".Analytical Biochemistry. 176 (1): 28–32.

[3] "Introduction to Bioluminescence Assays". Promega Corporation. Retrieved2009-03-07.

[4]  Anderson, JM; Charbonneau, H; Cormier, MJ (12 March 1974). "Mechanism of calcium induction of Renilla bioluminescence. Involvement of a calcium-triggered luciferin binding protein.".Biochemistry. 13 (6): 1195–200

[5]Fan F, Wood KV (Feb 2007). "Bioluminescent assays for high-throughput screening". ASSAY and Drug Development Technologies. 5 (1): 127–36.

Sequence and Features