Using Engineered Scaffold Interactions to Reshape MAP Kinase Pathway Signaling Dynamics
Caleb J. Bashor,1,2
Noah C. Helman,1
Shude Yan,1
Wendell A. Lim1*
Scaffold proteins link signaling molecules into linear pathways by physically assembling them into complexes. Scaffolds may also have a higher-order role as signal-processing hubs, serving as the target of feedback loops that optimize signaling amplitude and timing. We demonstrate that the Ste5 scaffold protein can be used as a platform to systematically reshape output of the yeast mating MAP kinase pathway. We constructed synthetic positive- and negative-feedback loops by dynamically regulating recruitment of pathway modulators to an artificial binding site on Ste5. These engineered circuits yielded diverse behaviors: ultrasensitive dose response, accelerated or delayed response times, and tunable adaptation. Protein scaffolds provide a flexible platform for reprogramming cellular responses and could be exploited to engineer cells with novel therapeutic and biotechnological functions.
1 Department of Cellular and Molecular Pharmacology, University of California at San Francisco, 600 16th Street, San Francisco, CA 94158, USA.
2 Graduate Group in Biophysics, University of California at San Francisco, 600 16th Street, San Francisco, CA 94158, USA.
* To whom correspondence should be addressed. E-mail: lim{at}cmp.ucsf.edu
