Figure 1.

Engineering cells. (a) Boolean logic can be programmed in cells using synthetic gene circuits to enable decision-making. Cells process inputs and when the logic input is true, the gene of interest (GOI) turns on (green). (b) DNA is transcribed into mRNA (red line) in the nucleus (1) and transported into the cytoplasm where it binds to a ribosome to be translated into protein (blue circles) (2). Transcriptional-based cellular reprogramming targets DNA located in the nucleus, whereas post-transcriptional-based reprogramming targets RNA in the cytoplasm. (c) An engineered communication system was built with engineered sender and receiver cells using coiled coils. In the absence of doxycycline (Dox), the coiled coils are not produced, and the receiver cell is in the off-state. (d) In the presence of Dox, the coiled coils are produced and bind to their cognate Epo receptors on the receiver cells. Upon binding, the STAT3 protein (gray ball) is released and translocates to the nucleus to activate the transcription of secreted alkaline phosphatase, which is secreted by the receiver cell (purple balls).