# Sea Pansy (Renilla reniformis)

1. May 5, 2004

### Monique

Staff Emeritus
I always thought Renilla was a beetle for some reason.. apparently it is a polyp.. I just found out.. but why is it called a pansy? It doesn't look like the flower at all?

Also, it says it produces green fluorescent protein, is that right? I thought it produced a luciferin analog.. the jellyfish Aequoria victoria is the one from which GFP was isolated. But I guess polyps and jellyfish are related.

So does anyone know the connection between luciferin, renilla and gfp?

2. May 5, 2004

Does this help?:

• Luminescence. 2002 Jan-Feb;17(1):43-74.

Imaging of light emission from the expression of luciferases in living cells and organisms: a review.

Greer LF 3rd, Szalay AA.

Department of Biochemistry, School of Medicine and Department of Natural Sciences-Biology Section, Loma Linda University, Loma Linda, CA 92354, USA.

Luciferases are enzymes that emit light in the presence of oxygen and a substrate (luciferin) and which have been used for real-time, low-light imaging of gene expression in cell cultures, individual cells, whole organisms, and transgenic organisms. Such luciferin-luciferase systems include, among others, the bacterial lux genes of terrestrial Photorhabdus luminescens and marine Vibrio harveyi bacteria, as well as eukaryotic luciferase luc and ruc genes from firefly species (Photinus) and the sea pansy (Renilla reniformis), respectively. In various vectors and in fusion constructs with other gene products such as green fluorescence protein (GFP; from the jellyfish Aequorea), luciferases have served as reporters in a number of promoter search and targeted gene expression experiments over the last two decades. Luciferase imaging has also been used to trace bacterial and viral infection in vivo and to visualize the proliferation of tumour cells in animal models. Copyright 2002 John Wiley & Sons, Ltd.

PMID: 11816060

Last edited: May 5, 2004
3. May 5, 2004

### Monique

Staff Emeritus
A 32 paged review article.. sure it must :D If only I could get the computer to start printing again.. I like what you did with the post layout :)

4. May 5, 2004

### Moonbear

Staff Emeritus
Well, I suppose there could be a difference in semantics between saying it produces A green fluorescent protein and THE green fluorescent protein. Luciferins, I think, have a similar spectrum to GFP (I'm familiar with a compound called lucifer yellow that at least is detected with the same filters as GFP on our fluorescent scope...not sure if that's a natural compound or something someone generated in the lab, but the name seems to suggest it's at least based on luciferins...I dunno for sure though...the spectra aren't identical, but I think they are similar).

5. May 5, 2004

The five basic luciferin–luciferase systems

• Phylogeny and evolution

Luciferase is a generic name because none of the major luciferases share sequence homology with each other (5). Luciferases occur in bacteria, fungi, dinoflagellates, radiolarians and about 17 metazoan phyla and 700 genera, mostly marine (5, 12, 13).

Luciferin–luciferase-protein light-emitting systems

Bioluminescence is a chemiluminescent reaction between at least two molecules produced under physiological conditions within or in association with an organism. The substrate molecule reacted upon, which emits light in such a reaction, is called a luciferin. Luciferases are a wide range of enzymes that catalyse the oxidation of substrate luciferins to yield non-reactive oxyluciferins and the release of photons of light (17–21). As luciferin substrates are used, they must be replenished, which usually occurs through diet. Some luciferins require the presence of a co-factor to undergo oxidation, such as FMNH$_{2} ^{+}$, Ca$^{2+}$ or ATP (22). Complexes that contain a luciferase, a luciferin, and generally requiring O$_2$ are also called photoproteins (12).

Although luciferin–luciferase bioluminescence is found in hundreds of taxa across many phyla, there are five basic luciferin–luciferase system (12):

• Bacterial luciferin is a reduced riboflavin phosphate (FMNH$_{2}$) that is oxidized by a luciferase in association with a long-chain aldehyde and an oxygen molecule. It is found in luminescent bacteria, certain fish, pyrosomes, and in some squids (e.g. Euprymna).

• Dinoflagellate luciferin resembles, and may be derived from, the porphyrin of chlorophyll. In the dinoflagellate Gonycaulax, this luciferin is conformationally shielded from luciferase at the basic pH of 8 but becomes free and accessible to oxidation near the more acidic pH of 6. A modification of this luciferin occurs in a herbivorous euphausiid shrimp, where it is apparently acquired by ingestion.

• Another luciferin, from the marine ostracod Vargula, is called vargulin. It also seems to be acquired by ingestion. It is also found in some fish species.

• Coelenterazine is the most widely known luciferin. It occurs in cnidarians, copepods, chaetognaths, ctenophores, decapod shrimps, mysid shrimps, radiolarians, and some fish taxa. Coelenterate luciferase activity is controlled by the concentration of Ca$^{2+}$ and shares homology with the calcium-binding protein calmodulin (5).

• Firefly luciferin (a benzothiazole) is found exclusively in fireflies (Photinus or Luciola). It has the unique property of requiring ATP as a co-factor to convert it to an active luciferin (5). It was realized early that firefly luciferin–luciferase could be used to determine the presence of ATP (23). This has become a standard ATP assay. For one example, since nickel alloys have been shown to have an adverse effect on respiratory metabolism in eukaryotic cell lines, the firefly luciferin–luciferase system has been used to document depressed levels of ATP in cells exposed to the alloys (24).

The luciferases most commonly used in experimental bioluminescent imaging applications include the bacterial luciferases (lux) from the marine genera Photobacterium and Vibrio, firefly luciferase (Photinus), aequorin (luciferase from the jellyfish Aequorea), vargulin (luciferase from the marine ostracod Vargula), oplophoran luciferase (deep-sea shrimp Oplophorus) and Renilla luciferase (anthozoan sea pansy, Renilla reniformis).

• Bacterial luciferase. Bacterial luciferase proteins were purified and isolated from the light organs of mid-depth fishes in the ocean (25, 26). It was known early that the catalytic site was on the $\alpha$ subunit (27). Belas et al. (1982) isolated and expressed luciferase genes from Vibrio harveyi in E. coli (28). Olsson et al. (1988) characterized the activity of the LuxA subunit of Vibrio harveyi luciferase by visualizing various luxA and luxB truncations, as well as a luxAB fusion expressed in E. coli (29). Olsson et al. (1989) furthermore made monomeric luxAB fusions and expressed them also in E. coli (30). The Vibrio harveyi luxA and luxB cDNAs were cloned and sequenced in the mid-1980s (31–33). The luxCDABE operon from the terrestrial bacterium Photorhabdus luminescens was cloned and sequenced and its product, luciferase, was characterized and published in 1991 (34).

• Firefly luciferase. The active sites and properties of firefly luciferase (Photinus) began to be characterized about 35 years ago (35–37). Firefly luciferase was purified and characterized in 1978 (19). The cDNA encoding the luciferase (Luc) from the firefly Photinus pyralis was cloned and expressed in E. coli by De Wet et al. (1985) (38).

• Vargulin. A cDNA for the luciferase gene from the marine ostracod Vargula hilgendorfii was cloned, sequenced and expressed in mammalian cells by Thompson et al. (1989) (39). They also discovered that Vargula luciferase expression requires only its substrate and molecular oxygen (but no co-factors), thus making it potentially more useful for mammalian expression systems (40). The activity of Vargula luciferase is not dependent on a pyrazine structure, as has been demonstrated by cross-reaction experiments with the Oplophorus luciferin (41).

• Aequorin. The aequorin protein was first extracted from the hydromedusa Aequorea, purified and characterized in part by Shimomura et al. (1962) (42). In 1975, Shimomura and Johnson described what was known about the mechanisms of various coelenterate luciferins, including aequorin (22). Ward and Cormier (1975) reported the isolation of various Renilla-type luciferins, including aequorin (43). A few years later, it was discovered that Renilla luciferin analogues were catalysed by luciferase to excited energy states to transfer energy to a green fluorescence protein or GFP (44). Ward and Cormier (1979) characterized the Renilla green fluorescence protein (RGFP) and showed that a natural energy transfer was occurring from the isolated Renilla luciferase (Ruc) bioluminescence to RGFP (45). In 1985, the cDNA for aequorin was cloned, sequenced and expressed in heterologous systems (46, 47). The aequorin gene from the jellyfish Aequorea victoria was cloned in 1990 (48). It is now known that many cnidarians have GFPs that serve as energy-transfer acceptors fluorescing in response to excited oxyluciferin–luciferase complexes or to a Ca$^{2+}$ -activated phosphoprotein. The cDNA encoding the GFP of Aequorea victoria has also been cloned and sequenced (49).

• Oplophorus luciferase. The general reaction mechanisms and properties of the luciferin–luciferase system of the deep-sea shrimp Oplophorus gracilorostris were reported by Shimomura et al. (1978) (50). An empirical formula and structure has been suggested for Oplophorus luciferin using spectroscopy and cross-reaction with the luciferase of the ostracod Vargula hilgendorfii (40). By 1997, Oplophorus luciferase was known to have a more intense light emission than either Renilla luciferase or the recombinant aequorin. However the Oplophorus luciferase cDNA, not yet cloned, could not be used as a reporter gene (51). Recently, Inouye et al. (2000) succeeded in cloning the Oplophorus luciferase cDNA (52).

• Renilla luciferase. In 1966, Hori and Cormier described some of the properties and a hypothetical partial structure for the Renilla reniformis luciferase protein (Ruc) (53). Kreis and Cormier (1967) showed that light could inhibit the activity of Ruc (54). The isolation of Ruc was first done and further properties elucidated by Karkhanis and Cormier (1971) (55). DeLuca et al. (1971) demonstrated that the Renilla bioluminescent system involves the oxidative production of CO$_{2}$ (56). It was further shown that Ca$^{2+}$ triggered a luciferin binding protein, thus inducing the Ruc system (57). Ruc was first purified and characterized by Matthews et al. (1977) (58). The cDNA of ruc was isolated and later expressed in E. coli by Lorenz et al. (1991) (59). The ruc cDNA was also expressed in a number of transgenic plant tissues (60). In 1996, Lorenz et al. expressed Ruc in simian COS-7 cells and in murine C5 cells (61).

Last edited: May 5, 2004
6. May 5, 2004

### Moonbear

Staff Emeritus
Thanks for the enlightening information ;-) Very interesting!