1. Programmable cells: Interfacing natural and engineered gene networks
Hideki Kobayashi, Mads Kærn, Michihiro Araki, Kristy Chung,
Timothy S. Gardner, Charles R. Cantor, and James J. Collins

2. Scope
create novel cellular behaviors and characteristics by coupling engineered gene networks to the cell’s natural regulatory circuitry
Four examples
Detects and retains memory of DNA damage
Forms biofilm in response to DNA damage
Detects and retains memory of quorum sensing molecules
Density dependent protein synthesis

4. Flow Cytometer (BD FcsCalibur)
Reporter: GFP

7. lacI -> lacR -> Ptrc -> lcI -> lcI -> PL

8. lacI -> lacR -> Ptrc -> lcI -> lcI -> PL

9. MMC – 15 h
UV – 1-10 s

10. Biofilm was only observed if traA was expressed for > 4h
(With traA gene)
(lacking the traA gene)
Replace
gfp with
traA
Biofilm was only observed if traA was expressed for > 4h

11. LuxI-LuxR quorum-sensing systems
acylated-homoserine lactone (AHL)
luxICDABE
luxR
LuxR
LuxI

12. lacI -> lacR -> Ptrc -> lcI -> lcI -> PL
Quorum sensing molecules
lacI -> lacR -> Ptrc -> lcI -> lcI -> PL

13. Density-dependent gene activation
Toggle
GFP
lacI -> lacR -> Ptrc -> lcI -> lcI -> PL

15. Discussions
Programmable cells have been constructed by interfacing natural and engineered gene networks
Programmable cells have been demonstrated using four different constructs with the toggle gene network as a building block

16. Something to think about…

17. DNA damage sensing Original design Modified design b)
Will the modified design work? If not, why not? If yes, how would it differ from (a)?

18. Density-dependent gene activation
gfp
Q: What if we replace the lacI gene with gfp and forget about the regulatory circuit