cell-cell communication, sensing and chemotaxis

Cell-Cell Communication, Sensing and Chemotaxis

N Kuldell for 20.020

Spring 2009

Heidelburg iGEM 2008: ecolicense to kill

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Part 1: Sensing

Background information

Cell-Cell Communication

natural context: Cuttlefish and Vibrio harveyi



Cuttlefish: master of camouflage

During the day they lie buried in the bottom of the ocean; at night they swim and hunt for food.




natural context: Cuttlefish and Vibrio harveyi



Photo from B. Bassler, Fig from:

Genes & Dev. 2001. 15: 1468-1480 doi: 10.1101/gad.899601

AI-2AI-1Few cells: Autoinducers diffuse

away

More cells: Autoinducers initiate

signaling, transcription

LuxS= enzyme that produces autoinducer 2 (AI2)…diffuses through the media

Prey Cell

Predator Cell

LuxP, LuxQ = receptor that binds (AI2)…induces chemotaxis….how?


iGEM context: “prey” pathogen, “predator” killer

Nature (2002) 415: 545

Sensing and Signaling Cascades

natural context: “TCS” 2 component signalingAI-2AI-1

TCS

“SHK” sensor histidine kinase

“RR” response regulator

Stimulus

Activates SHK

Transfers to RR

Output

P


natural context: “TCS” 2 component signaling

TCS

“SHK” sensor kinase


Stimulus

Activates SHK

Transfers to RR

Output

P

Plant Physiol. (1998) 117: 723


natural context: “TCS” 2 component signaling

TCS

“SHK” sensor kinase


Stimulus

Activates SHK

Transfers to RR

Output

P



CCW, default, tumble

CW, signal, swim

TarChe flagella

J Bacteriol. (2000)182: 6865


iGEM context: chimeric receptor