Complex mammalian cell circuit design*

7 August 2012 Last year, two groups used collections of modified yeast or bacterial cells to create biological systems that could respond to multiple inputs in a manner analogous to how a digital circuit processes information. Ausländer et al. now show…

7 August 2012

Last year, two groups used collections of modified yeast or bacterial cells to create biological systems that could respond to multiple inputs in a manner analogous to how a digital circuit processes information. Ausländer et al. now show that such behavior can be introduced into a single mammalian cell. The authors engineer human cells to enable them to perform one of the fundamental tasks of information processing systems—adding and subtracting single bits of information. In elementary school, children learning to add multidigit numbers are taught the concept of ‘carrying’ forward (e.g., to compute 29 plus 29, add the 9s, carry 1 forward and add the 2s plus the carried 1). Conceptually, the circuit of Ausländer et al. can perform a similar carrying operation, allowing it to add two single-digit binary numbers. In practical terms, the circuit takes as input two small molecules, the antibiotic erythromycin and the plant metabolite phloretin, and produces as outputs yellow and red fluorescent protein. The circuit marks a new standard of complexity achieved in synthetic biology. (Nature 487, 123–127, 2012)

 

Nature Biotechnology