While H-K two component systems have a natural purpose, past experiments have revealed that they can be manipulated so as to accomplish a specified goal. For example, Levskaya et al. generated a chimeric histidine kinase protein by identifying overlapping regions of proteins present in Synechocystis and Escherichia coli. By varying the length of the linking domain between the two proteins, Levskaya eventually grew bacteria that produced a pigment depending on the presence of red light, thus creating an effective bacterial camera using the “dark detector” (Levskaya et. al 2005). More recently, combining the dark detector with a Quorum sensing system led to the construction of an effective edge detector(Tabor et. al 2009). These displays of logic through cellular response give Histidine Kinases promise as another system through which to exert control over bacterial transcription.

For our work we will be attempting to recreate these proven systems. In order to do so, we will create MoClo parts for the protein domains and cognate promoters necessary for the functionality of the pathways. After replicating proven systems we plan to move toward generating our own H-K systems by combining different sensor and effector domains. Finally, using the Flow Cytometer will allow us to generate transfer functions for our histidine kinases and quantify their cellular responses. Ultimately, we hope to reinforce the usefulness of the modularity of MoClo and quantify the effectiveness of histidine kinase manipulation for the alteration of gene expression.

Reference

[1] Levskaya et. al "Synthetic Biology:engineering Escherichia coli to see light" Nature 2005;438:441–442

[2]Tabor et. al "A Synthetic Genetic Edge Detection Program" Cell. 2009 June 26; 137(7):1272-1281