Cyclic AMP is a critical mediator of intrinsic drug resistance and fatty acid metabolism in M. tuberculosis
- Rockefeller University, United States
- Weill Cornell Medicine, United States
- Cornell University, United States
Abstract
Cyclic AMP (cAMP) is a ubiquitous second messenger that transduces signals from cellular receptors to downstream effectors. Mycobacterium tuberculosis (Mtb), the etiological agent of tuberculosis, devotes a considerable amount of coding capacity to produce, sense, and degrade cAMP. Despite this fact, our understanding of how cAMP regulates Mtb physiology remains limited. Here, we took a genetic approach to investigate the function of the sole essential adenylate cyclase in Mtb H37Rv, Rv3645. We found that lack of rv3645 resulted in increased sensitivity to numerous antibiotics by a mechanism independent of substantial increases in envelope permeability. We made the unexpected observation that rv3645 is conditionally essential for Mtb growth only in the presence of long-chain fatty acids, a host-relevant carbon source. A suppressor screen further identified mutations in the atypical cAMP phosphodiesterase rv1339 that suppress both fatty acid and drug sensitivity phenotypes in strains lacking rv3645. Using mass spectrometry, we found that Rv3645 is the dominant source of cAMP under standard laboratory growth conditions, that cAMP production is the essential function of Rv3645 in the presence of long-chain fatty acids, and that reduced cAMP levels result in increased long-chain fatty acid uptake and metabolism and increased antibiotic susceptibility. Our work defines rv3645 and cAMP as central mediators of intrinsic multidrug resistance and fatty acid metabolism in Mtb and highlights the potential utility of small molecule modulators of cAMP signaling.
Data availability
RNA-seq data of Mtb H37Rv are deposited in NCBI's Sequence Read Archive (SRA) under BioProject PRJNA930437. Whole genome sequencing data for ΔmacE and derived spontaneous rescue mutants were deposited in NCBI's SRA under BioProject PRJNA811534. CRISPRi suppressor screen sequencing data was deposited in NCBI's SRA under BioProject PRJNA814682.
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Rv3645 palmitic acid CRISPRi suppressor screenNCBI BioProject, PRJNA814682.
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Mycobacterium tuberculosis rv3645 knockoutNCBI BioProject, PRJNA811534.
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WT Mtb H37Rv RNA-seqNCBI BioProject, PRJNA930437.
Article and author information
Author details
Funding
Bill and Melinda Gates Foundation (INV-004709)
- Kyu Y Rhee
National Institutes of Health (P01AI143575)
- Dirk Schnappinger
- Sabine Ehrt
National Institutes of Health (R01130018)
- Brian C VanderVen
NIH Tuberculosis Research Units Network (U19AI162584)
- Kyu Y Rhee
- Jeremy M Rock
Department of Defense (PR192421)
- Jeremy M Rock
Robertson Therapeutic Development Fund
- Jeremy M Rock
NIH/NIAID New Innovator Award (1DP2AI144850-01)
- Jeremy M Rock
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2023, Wong et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Cyclic AMP is a critical mediator of intrinsic drug resistance and fatty acid metabolism in M. tuberculosis
eLife 12:e81177.
https://doi.org/10.7554/eLife.81177
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