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Engineering signal processing in cells: Towards molecular concentration band detection

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We seek to couple protein-ligand interactions with synthetic gene networks in order to equip cells with the ability to process internal and environmental information in novel ways. In this paper, we propose and analyze a new genetic signal processing circuit that can be configured to detect various chemical concentration ranges of ligand molecules. These molecules freely diffuse from the environment into the cell. The circuit detects acyl-homoserine lactone ligand molecules, determines if the molecular concentration falls within two prespecified thresholds, and reports the outcome with a fluorescent protein. In the analysis of the circuit and the description of preliminary experimental results, we demonstrate how to adjust the concentration band thresholds by altering the kinetic properties of specific genetic elements, such as ribosome binding site efficiencies or dna-binding protein affinities to their operators.

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  • Ausubel FM, Brent R, Kingston RE, Moore DD, Seidman JG, Smith JA and Struhl K (1999) Short Protocols in Molecular Biology. Wiley

  • Bassler BL (1999) How bacteria talk to each other: Regulation of gene expression by quorum sensing. Current Opinion in Microbiology 2: 582–587

    Article  Google Scholar 

  • Becskei A and Serrano L (2000) Engineering stability in gene networks by autoregulation. Nature 405: 590–593

    Article  Google Scholar 

  • Elowitz M and Leibler S (2000) A synthetic oscillatory network of transcriptional regulators. Nature 403: 335–338

    Article  Google Scholar 

  • Fuqua WC, Winans S and Greenberg EP (1994) Quorum sensing in bacteria: The LuxR-LuxI family of cell density-responsive transcriptional regulators. J. Bacteriol 176: 269–275

    Google Scholar 

  • Gardner T, Cantor R and Collins J (2000) Construction of a genetic toggle switch in Escherichia coli. Nature 403: 339–342

    Article  Google Scholar 

  • Hendrix RW (1983) Lambda II. Cold Spring Harbor Press, Cold Spring Harbor, New York

    Google Scholar 

  • Ptashne M (1986) A Genetic Switch: Phage lambda and Higher Organisms, 2nd edition. Cell Press and Blackwell Scientific Publications, Cambridge, MA

    Google Scholar 

  • Sambrook J, Fritsch EF and Maniatis T (1989) Molecular Cloning: A Laboratory Manual. Cold Spring Harbor Laboratory Press, Plainview, NY

    Google Scholar 

  • Shapiro HM (1995) Practical Flow Cytometry, 3rd edition. Wiley-Liss, New York, NY

    Google Scholar 

  • Weiss R and Basu S (2002) The device physics of cellular logic gates. In: NSC-1: The First Workshop of Non-Silicon Computing. Boston, Massachusetts

  • Weiss R, Homsy G and Knight TF Jr. (1999) Toward in-vivo digital circuits. In: Dimacs Workshop on Evolution as Computation. Princeton, NJ

  • Weiss R and Knight TF Jr. (2000) Engineered communications for microbial robotics. In: DNA6: Sixth International Workshop on DNA-Based Computers, DNA2000, pp. 1–16. Leiden, The Netherlands, Springer-Verlag

    Google Scholar 

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Basu, S., Karig, D. & Weiss, R. Engineering signal processing in cells: Towards molecular concentration band detection. Natural Computing 2, 463–478 (2003).

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