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Tunable Temperature-Sensitive Transcriptional Activation Based on Lambda Repressor

Xiong, Lealia L. and Garrett, Michael A. and Buss, Marjorie T. and Kornfield, Julia A. and Shapiro, Mikhail G. (2022) Tunable Temperature-Sensitive Transcriptional Activation Based on Lambda Repressor. ACS Synthetic Biology, 11 (7). pp. 2518-2522. ISSN 2161-5063. PMCID PMC9295150. doi:10.1021/acssynbio.2c00093.

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Temperature is a versatile input signal for the control of engineered cellular functions. Sharp induction of gene expression with heat has been established using bacteria- and phage-derived temperature-sensitive transcriptional repressors with tunable switching temperatures. However, few temperature-sensitive transcriptional activators have been reported that enable direct gene induction with cooling. Such activators would expand the application space for temperature control. In this technical note, we show that temperature-dependent versions of the Lambda phage repressor CI can serve as tunable cold-actuated transactivators. Natively, CI serves as both a repressor and activator of transcription. Previously, thermolabile mutants of CI, known as the TcI family, were used to repress the cognate promoters PR and PL. We hypothesized that TcI mutants can also serve as temperature-sensitive activators of transcription at CI’s natural PRM promoter, creating cold-inducible operons with a tunable response to temperature. Indeed, we demonstrate temperature-responsive activation by two variants of TcI with set points at 35.5 and 38.5 °C in E. coli. In addition, we show that TcI can serve as both an activator and a repressor of different genes in the same genetic circuit, leading to opposite thermal responses. Transcriptional activation by TcI expands the toolbox for control of cellular function using globally or locally applied thermal inputs.

Item Type:Article
Related URLs:
URLURL TypeDescription CentralArticle
Xiong, Lealia L.0000-0001-7636-5936
Buss, Marjorie T.0000-0002-4266-9197
Kornfield, Julia A.0000-0001-6746-8634
Shapiro, Mikhail G.0000-0002-0291-4215
Additional Information:© 2022 The Authors. Published by American Chemical Society. Attribution 4.0 International (CC BY 4.0). Published online 16 June 2022. Published in issue 15 July 2022. The authors thank Mohamad Abedi, Cameron Smith, Di Wu, and Deepak Mishra for helpful discussions. Flow cytometry was performed at the Caltech Flow Cytometry Facility. This research was supported by the Defense Advanced Research Project Agency (HR0011-17-2-0037 to M.G.S. and J.A.K.) and the Institute for Collaborative Biotechnologies (W911NF-19-D-0001 to M.G.S.). L.L.X. and M.T.B. were supported by the NSF Graduate Research Fellowship Program. M.A.G. was supported by the NIH MBRS Research Initiative for Scientific Enhancement Program. M.G.S. is an Investigator of the Howard Hughes Medical Institute. Related research in the Shapiro lab is supported by the David & Lucile Packard Foundation and the Dreyfus Foundation. Author Contributions. L.L.X. and M.G.S. conceived the study. L.L.X., M.A.G., and M.T.B. planned and performed experiments. L.L.X. analyzed data. L.L.X. and M.G.S. wrote the manuscript with input from all other authors. M.G.S. and J.A.K. supervised the research. The authors declare no competing financial interest.
Funding AgencyGrant Number
Defense Advanced Research Projects Agency (DARPA)HR0011-17-2-0037
Army Research Office (ARO)W911NF-19-D-0001
NSF Graduate Research FellowshipDGE-1745301
Howard Hughes Medical Institute (HHMI)UNSPECIFIED
David and Lucile Packard FoundationUNSPECIFIED
Camille and Henry Dreyfus FoundationUNSPECIFIED
Subject Keywords:thermal control; temperature; transactivation; transcription factors; microbial synthetic biology
Issue or Number:7
PubMed Central ID:PMC9295150
Record Number:CaltechAUTHORS:20220720-917501000
Persistent URL:
Official Citation:Lealia L. Xiong, Michael A. Garrett, Marjorie T. Buss, Julia A. Kornfield, and Mikhail G. Shapiro ACS Synthetic Biology 2022 11 (7), 2518-2522 DOI: 10.1021/acssynbio.2c00093
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:115699
Deposited By: George Porter
Deposited On:25 Jul 2022 20:17
Last Modified:25 Jul 2022 20:17

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