Abstract

The long term objective of this project is to better understand how Mycobacterium tuberculosis (Mtb) establishes infection so that effective strategies can be developed to prevent it. Gene regulation is a critical aspect of Mtb's successful response to the host environment during infection. The recent finding that Mtb encodes as many as 15 adenylate cyclases (AC) suggests that cAMP signaling constitutes an important, but previously unrecognized, regulatory mechanism in Mtb. A multidisciplinary approach will address the role of cAMP signaling in Mtb, at the molecular, genetic and cellular levels, with a focus on conditions associated with latency and Mtb's interaction with macrophages.
Specific aims i nclude:
Aim 1 : identify, using DMA microarrays and isogenic knockout mutants, Mtb genes that are regulated by the putative cAMP-dependent transcription factor, Rv1675c, at various levels of cAMP during hypoxia;
Aim 2 : define and characterize a second likely cAMP-dependent regulon controlled by putative transcription factor Rv3676 in Mtb. Candidate members of this regulon will be functionally assessed by defining the role of Rv3676 binding to a DMA motif identified in their promoter regions;
Aim 3 : evaluate the roles of cAMP and a mammalian-type AC, Rv1625c, in Mtb's interaction with macrophages, particularly with respect to bacterial replication and trafficking;
Aim 4 : assess the regulation and function of a specific macrophage-induced, cAMP regulated gene within macrophages and during latency-associated conditions. Identification and characterization of cAMP-mediated gene regulation in Mtb will contribute to our understanding of the factors needed for the establishment of tuberculosis infection and disease. This work will explore a new gene regulatory network in Mtb and provide an important foundation for future work on the role of cAMP signaling in Mtb virulence gene regulation, leading to identification of potential targets for TB vaccines, therapeutics, and/ or diagnostic purposes.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
1R01AI063499-01A1
Application #
6989656
Study Section
Host Interactions with Bacterial Pathogens Study Section (HIBP)
Program Officer
Sizemore, Christine F
Project Start
2005-06-15
Project End
2010-02-28
Budget Start
2005-06-15
Budget End
2006-02-28
Support Year
1
Fiscal Year
2005
Total Cost
$240,312
Indirect Cost

  Institution

Name
Wadsworth Center
Department
Type
DUNS #
153695478
City
Menands
State
NY
Country
United States
Zip Code
12204

  Publications

Girardin, Roxie C; Bai, Guangchun; He, Jie et al. (2018) AbmR (Rv1265) is a novel transcription factor of Mycobacterium tuberculosis that regulates host cell association and expression of the non-coding small RNA Mcr11. Mol Microbiol 110:811-830
DeMott, Christopher M; Girardin, Roxie; Cobbert, Jacqueline et al. (2018) Potent Inhibitors of Mycobacterium tuberculosis Growth Identified by Using in-Cell NMR-based Screening. ACS Chem Biol 13:733-741
Ranganathan, Sridevi; Cheung, Jonah; Cassidy, Michael et al. (2018) Novel structural features drive DNA binding properties of Cmr, a CRP family protein in TB complex mycobacteria. Nucleic Acids Res 46:403-420
Johnson, Richard M; Bai, Guangchun; DeMott, Christopher M et al. (2017) Chemical activation of adenylyl cyclase Rv1625c inhibits growth of Mycobacterium tuberculosis on cholesterol and modulates intramacrophage signaling. Mol Microbiol 105:294-308
Ranganathan, Sridevi; Bai, Guangchun; Lyubetskaya, Anna et al. (2016) Characterization of a cAMP responsive transcription factor, Cmr (Rv1675c), in TB complex mycobacteria reveals overlap with the DosR (DevR) dormancy regulon. Nucleic Acids Res 44:134-51
Cobbert, Jacqueline D; DeMott, Christopher; Majumder, Subhabrata et al. (2015) Caught in action: selecting peptide aptamers against intrinsically disordered proteins in live cells. Sci Rep 5:9402
Knapp, Gwendowlyn S; Lyubetskaya, Anna; Peterson, Matthew W et al. (2015) Role of intragenic binding of cAMP responsive protein (CRP) in regulation of the succinate dehydrogenase genes Rv0249c-Rv0247c in TB complex mycobacteria. Nucleic Acids Res 43:5377-93
McDonough, Kathleen A; Rodriguez, Ana (2011) The myriad roles of cyclic AMP in microbial pathogens: from signal to sword. Nat Rev Microbiol 10:27-38
Bai, Guangchun; Schaak, Damen D; Smith, Eric A et al. (2011) Dysregulation of serine biosynthesis contributes to the growth defect of a Mycobacterium tuberculosis crp mutant. Mol Microbiol 82:180-98
Bai, Guangchun; Knapp, Gwendowlyn S; McDonough, Kathleen A (2011) Cyclic AMP signalling in mycobacteria: redirecting the conversation with a common currency. Cell Microbiol 13:349-58

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