IGEM:Imperial/2010/Rapid Response Sensor System

Rapid Response system relying on pre-produced pigments or fluorescent proteins.

RAPID RESPONSE MODULE

Using linked 2 component systems we will create a logic gate type system with AND, OR functions. The effector protein in the response relay chain will activate expression of a protease which will induce sequestered pigment dispersal.

This system will have multiple colour outputs, at it simplest we can work with 3 coloured outputs responding to 2 different stimuli by using a combination of two pigments to make the 3rd colour.

The pre-made pigments or fluorescent proteins will be sequestered onto a scaffold protein via linking sequences. These will contain proteolytic cleavage sites unique to each coloured pigment. Proteases activated by a particular 2 component system will cleave off pigments of one colour. Therefore single or combinations of activated 2 component systems will produce a particular coloured pigment release.

The types of pigment that we've considered include bilins and phytochromes (or non fluorescent pigments that can be tagged), the family of fluorescent proteins and camgaroos.

An alternative to the scaffold sequestering idea is to create a poly-cistronic chain of linked pigments which can then be cleaved into single entities.

Use colourless to coloured response is the best approach. So two interacting proteins on the scaffold type molecule are colourless, upon cleavage the interaction is broken and colour is visualized.

Using inteins to activate an enzyme by-passing the transcription-translation step.

Fret based output system using quenchers as an alternative to bilins. Proof of principle techniques exist (caspase detection experiment)

Research into natural proteases that are activated by phosphorylation or an alternative.