Lizcano, A. et al. (2017) Transcriptional organization of pneumococcal psrP-secY2A2 and impact of GtfA and GtfB deletion on PsrP-associated virulence properties. Microbes and Infection, 19(6), pp. 323-333. (doi: 10.1016/j.micinf.2017.04.001) (PMID:28408270)
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Abstract
Pneumococcal serine-rich repeat protein (PsrP) is a glycoprotein that mediates Streptococcus pneumoniae attachment to lung cells and promotes biofilm formation. Herein, we investigated the transcriptional organization of psrP-secY2A2, the 37-kbp pathogenicity island encoding PsrP and its accessory genes. PCR amplification of cDNA and RNA-seq analysis found psrP-secY2A2 to be minimally composed of three operons: psrP-glyA, glyB, and glyC-asp5. Transcription of all three operons was greatest during biofilm growth and immunoblot analyses confirmed increased PsrP production by biofilm pneumococci. Using gas chromatography-mass spectrometry we identified monomeric N-acetylglucosamine as the primary glycoconjugate present on a recombinant intracellular version of PsrP, i.e. PsrP1-734. This finding was validated by immunoblot using lectins with known carbohydrate specificities. We subsequently deleted gtfA and gtfB, the GTFs thought to be responsible for addition of O-linked N-acetylglucosamine, and tested for PsrP and its associated virulence properties. These deletions negatively affected our ability to detect PsrP1-734 in bacterial whole cell lysates. Moreover, S. pneumoniae mutants lacking these genes pheno-copied the psrP mutant and were attenuated for: biofilm formation, adhesion to lung epithelial cells, and pneumonia in mice. Our studies identify the transcriptional organization of psrP-secY2A2 and show the indispensable role of GtfA and GtfB on PsrP-mediated pneumococcal virulence.
| Item Type: | Articles |
|---|---|
| Additional Information: | Support for AL was from the Translational Science Training Across Discipline Program UL-1RR025767 at UTHSCSA and NIH AI104298. Support for CJO was from NIH AI078972 and AI114800. |
| Keywords: | Biofilms, glycosylation, PsrP, serine-rich repeat proteins, streptococcus pneumoniae, transcription, virulence. |
| Status: | Published |
| Refereed: | Yes |
| Glasgow Author(s) Enlighten ID: | Mitchell, Professor Timothy |
| Authors: | Lizcano, A., Akula Suresh Babu, R., Shenoy, A. T., Saville, A. M., Kumar, N., D'Mello, A., Hinojosa, C. A., Gilley, R. P., Segovia, J., Mitchell, T. J., Tettelin, H., and Orihuela, C. J. |
| College/School: | College of Medical Veterinary and Life Sciences > School of Infection & Immunity |
| Journal Name: | Microbes and Infection |
| Publisher: | Elsevier |
| ISSN: | 1286-4579 |
| ISSN (Online): | 1769-714X |
| Published Online: | 10 April 2017 |
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