We have tried to create art as well as present the new art tools for artists. New tools will open the new possibility for art. We want to provide the outstanding painting tools. So far, we have built some fluorescence protein and organic pigments into our art tool ‘colacoli’. We want to make as many painting color tools as possible.

Color is important factor for art. Colors of 'colacoli' is consisted of fluorescence colors and pigment colors. Fluorescence colors are red, green, cyan, yellow, and orange. They are from RFP, GFP, CFP,YFP, and mOrange respectively. We need more colors as possible, but couldn't find DNAs cording fluorescence colors in iGEM parts registry. So we adopted a different method for colors, that is pigment. Pigment colors are red, orange, yellow, brown, black, and purple.Red, orange, and yellow are carotenoid, brown and black are melanin and purple is violacein colors.

Fluorescence

We assembled genetic circuits for fluorescence colors. We have two patterns that is attached to promoters, p(Lac) or p(Tet),respectively.

p(Lac) colors p(Tet) colors

Carotenoid

Carotenoid is a family of natural pigments. Many plants such as fruits and vegetables have this pigments. For example, tomato has lycopene(red), carrot has carotene(orange). Xanthophyll(yellow) is in almost plants.

Biosynthesis of carotenoid pigments starts from FPP(FARNESYL DIPHOSPHATE). FPP is formed from isopentenylpyrophosphate(IPP) and dimethylallylpyrophosphate(DMAPP).

IPP and DMAPP are formed in mevalonate pathway or nonmevalonate pathway. Mevalonate pathway is an important cellular metabolic pathway present in all higher eukaryotes and many bacteria. And nonmevalone pathway is to produce isoprenoids in plants and apicomplexan protozoa

Mevalonate pathway

Non mavalonate pathway

We succeeded the circuit for carotene(orange). But the color of cell is very weak, and looks cream color.

Melanin

Melanin is a pigment that is maked in human body. There are brown-black melanin pigments and orange-red melanin pigments. For example, our hair contains melanin as a major ingredient. So the quantity of melanin makes natural hair color.

Biosynthesis of melanin pigments starts from tyrosine which is one of the amino acids. Tyrosine is changed to dopa and dopaquinone by the action of tyrosinase. Finally products become brown-black melanin.

Violacein

Violacein is a purple pigment. Bacteria in deep seawater produses this pigments. Violacein have antibacterial action, antitumor action, and so on.

Biosynthesis of violacein pigments starts from tryptophan. As a substrate with tryptophan, to produse violacein needs enzyme vioA - vioE.

We assembled the genetic circuits that turn on their colors by sensor switch. When a receiver of a sensor get a signal, a downstream gene for a color is activated. Without signals, they have no colors.

But We couldn't make perfect on/off system. However it is without signals, their colors is expressed in some degree. The sensor makes a difference in the level of expression. So we made use of the difference to check the ability of sensor. Shown these circuit below.

p(TetR)+RBS+Receiver(see SIGNAL.)+tt+P(Receiver+signal)+RBS+color+tt

Color gradation

We plan the genetic circuit which gradually changes cell color. This gene circuit indicates bellow. This is an application of our signal circuit. Signal system includes 2 distinct groups of parts: 'Senders' and 'Receivers'. The specific promoter in the receiver cells is activated by receiving the AHL signal from the sender cells. (see SIGNAL.)

On this application circuit, the gene coding different color protein from initial color, CI lambda protein gene, and AHL protein gene are on downstream of AHL-activated promoter. CI lambda protein is the repressor of CI promoter which regulates the initial color protein. Therefore, when the signal is received, the cell gradually starts expression of the new color protein and stops expression of initial color protein. In addition, the receiver cells have roles as sender cells against same receiving cell. The signal is conveyed from the cell to the cell. As a result cell color gradually changes. Planning circuit is below.

Below movie indicates ideal results. The simulation movie includes an unknown parameter because of no experiment. This is ideal plan.