Scientists Create Proteins That Don't Crosstalk with Other Molecules

This research could assist synthetic biologists in the future.
Fabienne Lang

Cells in our bodies communicate important messages via interactions between proteins. In order for these messages to be clearly and accurately conveyed, every protein needs to talk to only one other partner, cutting out any crosstalk with other similar proteins. 

A new MIT study has unveiled how crosstalk between these proteins can be avoided by using cells. Furthermore, the study has also shown how there are many more potential protein interactions that cells have yet to use. 

This could assist synthetic biologists in creating new pairs of proteins to act as artificial circuits — which would be useful when diagnosing diseases.


New study and new combinations

The MIT researchers created new pairs of signaling proteins to show how these can be useful in linking new signals to new outputs by engineering E. coli cells.

"Using our high-throughput approach, you can generate many orthogonal versions of a particular interaction, allowing you to see how many different insulated versions of that protein complex can be built," said Conor McClune, an MIT graduate student and the lead author of the study.

In their study, the researchers used a two-component signaling pathway that is found in bacteria. These pathways have evolved through a process that allows cells to duplicate genes to signal proteins they already have. Then they mutate them and end up creating similar protein groupings.

“It’s intrinsically advantageous for organisms to be able to expand this small number of signaling families quite dramatically, but it runs the risk that you’re going to have crosstalk between these systems that are all very similar," said Michael Laub, MIT professor of Biology and senior author of the study.

Laub continued, "It then becomes an interesting challenge for cells: How do you maintain the fidelity of information flow, and how do you couple specific inputs to specific outputs?"

Finally, Laub said, "What we found is that it’s pretty easy to find combinations that will work, where two proteins interact to transduce a signal, and they don’t talk to anything else inside the cell."

Synthetic biology

What the study also assists with is a new strategy for creating synthetic circuits. One of the applications could be designing circuits that notice the presence of other microbes. These circuits could prove useful when creating probiotic bacteria, which helps diagnose infectious diseases. 

"Bacteria can be engineered to sense and respond to their environment, with widespread applications such as ‘smart’ gut bacteria that could diagnose and treat inflammation, diabetes, or cancer, or soil microbes that maintain proper nitrogen levels and eliminate the need for fertilizer," said Jeffrey Tabor, an associate professor of bioengineering and biosciences at Rice University.