quorum sensing, two component signaling and bacterial photography
Post on 24-Dec-2015
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Quorum sensing, Two component signaling and
Bacterial Photography
With the two component bacterial photography system bacteria can grow light or dark and take “photos” like these…
The genetic system that produces these is complicated. It is based on the two component signaling system found in bacteria. It is related to quorum sensing.
PigmentLight
SensorDevice
Actuator Device
S-gal pigmentCph8
OmpR regulated
LacZ
This two component signaling system consists of the following parts:
The Sensor (labeled PCB)The Regulator (ompR)/transcription factorThe Promoter (ompC)The RBS (not indicated)The Open Reading frame (lacZ)The Terminator sequence (not indicated)
P
OmpRLight
SensorCph8
Lac Z On
No light
In the dark:The Cph8 sensor is stimulatedOmpR (a transcription factor) is phosphorylatedWhich activates the promoterLac Z gene is expressedBeta gal enzyme is madeBeta gal converts S-gal into pigment
And the media becomes dark.
B-gal is produced
Dark pigment
What happens in the bacterial photography system?
Light SensorCph8
OmpR No B-gal
light Lac Z Off
In the light:The Cph8 sensor is not stimulatedOmpR (a transcription factor) is dephosphorylatedPromoter is not activeLac Z gene is not expressedNo Beta gal to convert S-gal into pigmentSo no pigment is produced by the bacteria and the
pigment stays light
No Pigment
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