Transcriptional activation of ompA in Neisseria gonorrhoeae mediated by the XRE family member protein NceR
ABSTRACT Increasing antibiotic resistance of Neisseria gonorrhoeae, the causative agent of gonorrhea, is a growing global concern that has renewed vaccine development efforts. The gonococcal OmpA protein was previously identified as a vaccine candidate due to its surface exposure, conservation, stab...
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| Format: | Article |
| Language: | English |
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American Society for Microbiology
2023-08-01
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| Series: | mBio |
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| Online Access: | https://journals.asm.org/doi/10.1128/mbio.01244-23 |
| _version_ | 1797730227175030784 |
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| author | Concerta L. Holley Vijaya Dhulipala Stavaros A. Maurakis Ashley Nicole Greenawalt Timothy D. Read Cynthia N. Cornelissen William M. Shafer |
| author_facet | Concerta L. Holley Vijaya Dhulipala Stavaros A. Maurakis Ashley Nicole Greenawalt Timothy D. Read Cynthia N. Cornelissen William M. Shafer |
| author_sort | Concerta L. Holley |
| collection | DOAJ |
| description | ABSTRACT Increasing antibiotic resistance of Neisseria gonorrhoeae, the causative agent of gonorrhea, is a growing global concern that has renewed vaccine development efforts. The gonococcal OmpA protein was previously identified as a vaccine candidate due to its surface exposure, conservation, stable expression, and involvement in host–cell interactions. We previously demonstrated that the transcription of ompA can be activated by the MisR/MisS two-component system. Interestingly, earlier work suggested that the availability of free iron also influences ompA expression, which we confirmed in this study. In the present study, we found that iron regulation of ompA was independent of MisR and searched for additional regulators. A DNA pull-down assay with the ompA promoter from gonococcal lysates obtained from bacteria grown in the presence or absence of iron identified an XRE (Xenobiotic Response Element) family member protein encoded by NGO1982. We found that an NGO1982 null mutant of N. gonorrhoeae strain FA19 displayed a reduced level of ompA expression compared to the wild-type (WT) parent strain. Given this regulation, and the capacity of this XRE-like protein to regulate a gene involved in peptidoglycan biosynthesis (ltgA), along with its presence in other Neisseria sp., we termed the NGO1982-encoded protein as NceR (Neisseria cell envelope regulator). Critically, results from DNA-binding studies indicated that NceR regulates ompA through a direct mechanism. Thus, ompA expression is subject to both iron-dependent (NceR) and -independent (MisR/MisS) pathways. Hence, levels of the vaccine antigen candidate OmpA in circulating gonococcal strains could be influenced by transcriptional regulatory systems and the availability of iron. IMPORTANCE Herein, we report that the gene encoding a conserved gonococcal surface-exposed vaccine candidate (OmpA) is activated by a heretofore undescribed XRE family transcription factor, which we term NceR. We report that NceR regulation of ompA expression in N. gonorrhoeae is mediated by an iron-dependent mechanism, while the previously described MisR regulatory system is iron-independent. Our study highlights the importance of defining the complexity of coordinated genetic and physiologic systems that regulate genes encoding vaccine candidates to better understand their availability during infection. |
| first_indexed | 2024-03-12T11:41:07Z |
| format | Article |
| id | doaj.art-00b1562d94a64e4bb7d0a79dcbc5ae41 |
| institution | Directory Open Access Journal |
| issn | 2150-7511 |
| language | English |
| last_indexed | 2024-03-12T11:41:07Z |
| publishDate | 2023-08-01 |
| publisher | American Society for Microbiology |
| record_format | Article |
| series | mBio |
| spelling | doaj.art-00b1562d94a64e4bb7d0a79dcbc5ae412023-08-31T15:04:20ZengAmerican Society for MicrobiologymBio2150-75112023-08-0114410.1128/mbio.01244-23Transcriptional activation of ompA in Neisseria gonorrhoeae mediated by the XRE family member protein NceRConcerta L. Holley0Vijaya Dhulipala1Stavaros A. Maurakis2Ashley Nicole Greenawalt3Timothy D. Read4Cynthia N. Cornelissen5William M. Shafer6Department of Microbiology and Immunology, Emory University School of Medicine , Atlanta, Georgia, USADepartment of Microbiology and Immunology, Emory University School of Medicine , Atlanta, Georgia, USAInstitute for Biomedical Sciences, Georgia State University , Atlanta, Georgia, USAInstitute for Biomedical Sciences, Georgia State University , Atlanta, Georgia, USADepartment of Medicine (Division of Infectious Diseases), Emory University School of Medicine , Atlanta, Georgia, USAInstitute for Biomedical Sciences, Georgia State University , Atlanta, Georgia, USADepartment of Microbiology and Immunology, Emory University School of Medicine , Atlanta, Georgia, USAABSTRACT Increasing antibiotic resistance of Neisseria gonorrhoeae, the causative agent of gonorrhea, is a growing global concern that has renewed vaccine development efforts. The gonococcal OmpA protein was previously identified as a vaccine candidate due to its surface exposure, conservation, stable expression, and involvement in host–cell interactions. We previously demonstrated that the transcription of ompA can be activated by the MisR/MisS two-component system. Interestingly, earlier work suggested that the availability of free iron also influences ompA expression, which we confirmed in this study. In the present study, we found that iron regulation of ompA was independent of MisR and searched for additional regulators. A DNA pull-down assay with the ompA promoter from gonococcal lysates obtained from bacteria grown in the presence or absence of iron identified an XRE (Xenobiotic Response Element) family member protein encoded by NGO1982. We found that an NGO1982 null mutant of N. gonorrhoeae strain FA19 displayed a reduced level of ompA expression compared to the wild-type (WT) parent strain. Given this regulation, and the capacity of this XRE-like protein to regulate a gene involved in peptidoglycan biosynthesis (ltgA), along with its presence in other Neisseria sp., we termed the NGO1982-encoded protein as NceR (Neisseria cell envelope regulator). Critically, results from DNA-binding studies indicated that NceR regulates ompA through a direct mechanism. Thus, ompA expression is subject to both iron-dependent (NceR) and -independent (MisR/MisS) pathways. Hence, levels of the vaccine antigen candidate OmpA in circulating gonococcal strains could be influenced by transcriptional regulatory systems and the availability of iron. IMPORTANCE Herein, we report that the gene encoding a conserved gonococcal surface-exposed vaccine candidate (OmpA) is activated by a heretofore undescribed XRE family transcription factor, which we term NceR. We report that NceR regulation of ompA expression in N. gonorrhoeae is mediated by an iron-dependent mechanism, while the previously described MisR regulatory system is iron-independent. Our study highlights the importance of defining the complexity of coordinated genetic and physiologic systems that regulate genes encoding vaccine candidates to better understand their availability during infection.https://journals.asm.org/doi/10.1128/mbio.01244-23Neisseria gonorrhoeaeompAregulationNceRiron |
| spellingShingle | Concerta L. Holley Vijaya Dhulipala Stavaros A. Maurakis Ashley Nicole Greenawalt Timothy D. Read Cynthia N. Cornelissen William M. Shafer Transcriptional activation of ompA in Neisseria gonorrhoeae mediated by the XRE family member protein NceR mBio Neisseria gonorrhoeae ompA regulation NceR iron |
| title | Transcriptional activation of ompA in Neisseria gonorrhoeae mediated by the XRE family member protein NceR |
| title_full | Transcriptional activation of ompA in Neisseria gonorrhoeae mediated by the XRE family member protein NceR |
| title_fullStr | Transcriptional activation of ompA in Neisseria gonorrhoeae mediated by the XRE family member protein NceR |
| title_full_unstemmed | Transcriptional activation of ompA in Neisseria gonorrhoeae mediated by the XRE family member protein NceR |
| title_short | Transcriptional activation of ompA in Neisseria gonorrhoeae mediated by the XRE family member protein NceR |
| title_sort | transcriptional activation of ompa in neisseria gonorrhoeae mediated by the xre family member protein ncer |
| topic | Neisseria gonorrhoeae ompA regulation NceR iron |
| url | https://journals.asm.org/doi/10.1128/mbio.01244-23 |
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