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Bacterial Second Messenger Cyclic di-AMP Modulates the Competence State in Streptococcus pneumoniae
Tiffany M Zarrella1, Jun Yang1, Dennis W Metzger1
1Department of Immunology and Microbial Disease, Albany Medical College, Albany, New York, USA.
Journal of Bacteriology
|November 27, 2019
Summary
The bacterial second messenger cyclic di-AMP (c-di-AMP) regulates competence in Streptococcus pneumoniae. This study reveals c-di-AMP
Area of Science:
- Microbiology
- Molecular Biology
- Bacterial Pathogenesis
Background:
- Streptococcus pneumoniae is a pathogen causing pneumonia and other diseases.
- Cyclic di-AMP (c-di-AMP) is a bacterial second messenger involved in stress responses.
- Pneumococcal competence facilitates horizontal gene transfer, impacting virulence and antibiotic resistance.
Purpose of the Study:
- To investigate the role of c-di-AMP in regulating the competence program of S. pneumoniae.
- To elucidate c-di-AMP-mediated transcriptional changes affecting pneumococcal pathogenesis.
- To understand the interplay between c-di-AMP, competence, and potassium ion (K+) transport.
Main Methods:
- Transcriptome sequencing (RNA-Seq) to compare wild-type and Δpde1 Δpde2 S. pneumoniae strains.
- Analysis of gene expression related to competence, DNA uptake, and recombination.
- Assessment of transformation efficiency and bacterial growth under varying conditions.
Main Results:
- Deletion of phosphodiesterases Pde1 and Pde2 upregulated competence-associated genes.
- The Δpde1 Δpde2 strain showed reduced, c-di-AMP-dependent transformation efficiency.
- c-di-AMP levels influenced susceptibility to competence-stimulating peptide (CSP) and K+ uptake via TrkH.
Conclusions:
- Cyclic di-AMP plays a novel regulatory role in the S. pneumoniae competence program.
- c-di-AMP modulates transformation efficiency, autolysis, and survival under stress.
- This study provides new insights into pneumococcal competence regulation and its link to c-di-AMP signaling.
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