Streptococcus pyogenes can cause a wide variety of acute infections throughout the body of its human host. Among more than 200 serotypes of S. pyogenes, serotype M1 strains hold the greatest clinical relevance due to their high prevalence in severe human infections. Genome-scale models (GEMs) play a crucial role in investigating bacterial metabolism, predicting the effects of inhibiting specific metabolic genes and pathways, and aiding in the identification of potential drug targets. We recently developed the first GEM for S. pyogenes M1 serotype (mSystems. 2024. PMID: 39158303). Independent component analysis (ICA) is a framework that decomposes a compendium of RNA-sequencing (RNA-seq) expression profiles to determine the underlying regulatory structure of a bacterial transcriptome. Using ICA, we identified 42 independently modulated gene sets (iModulons) for S. pyogenes M1 serotype and calculated their corresponding activity levels under each experimental condition (mSystems. 2023. PMID: 37278526). In this poster presentation, we demonstrate how GEMs and iModulon are useful to analyze RNA-seq data from S. pyogenes cultured in chemically defined medium. First, we introduce novel findings derived from the integration of metabolic gene expression differences into GEMs. Then, we demonstrate how iModulons can be leveraged to generate new hypotheses from RNA-seq analysis. These two systems biology techniques, GEMs and iModulons, provide powerful tools for uncovering the regulatory and metabolic mechanisms underlying Streptococcus pyogenes M1 serotype.
Author Contributions
Y.H., B.O.P. and V.N. contributed to the conceptualization of the study. Methodology was developed by Y.H. and B.O.P., and software was implemented by B.O.P. The investigation, formal analysis, and data curation were conducted by Y.H. Supervision was provided by V.N. and B.O.P.; Visualization and original draft preparation were completed by Y.H. The manuscript was reviewed and edited by E.I., M.O. and M.Y. Funding acquisition was led by M.Y., V.N. and B.O.P., and project administration was managed by Y.H., B.O.P. and V.N. All authors have read and agreed to the published version of the manuscript.
Funding
This study was supported in part by AMED (JP23wm0325066), and JSPS KAKENHI (25K00123, 25K028040, 23KK0281).
Institutional Review Board Statement
Not applicable.
Informed Consent Statement
Not applicable.
Data Availability Statement
All RNA-seq data generated in this study are available from the DDBJ Sequence Read Archive under accession number DRA014564. The code for quality control, ICA, and regulatory analysis is available on GitHub (modulome-workflow; PyModulon). Interactive dashboards are hosted at iModulonDB under “S. pyogenes”. The curated genome-scale metabolic models (iYH543 and variants) and simulation code are available at Osaka Univ. lab website (http://www.dent.osaka-u.ac.jp/wp-content/uploads/2024/03/Code_Model_Files_Hirose_et_al.zip).
Conflicts of Interest
The authors declare no conflict of interest.
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