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Peptidyl-prolyl cis/trans isomerases (PPIases) are enzymes that assist in protein folding around proline-peptide bonds, and they often possess chaperone activity. Staphylococcus aureus encodes three PPIases, i.e., PrsA, PpiB, and trigger factor (TF). Previous work by our group demonstrated a role for both PrsA and PpiB in S. aureus; however, TF remains largely unstudied. Here, we identify a role for TF in S. aureus biofilm formation and demonstrate cooperation between TF and the cytoplasmic PPIase PpiB. Mutation of the tig gene (encoding TF) led to reduced biofilm development in vitro but no significant attenuation of virulence in a mouse model of infection. To investigate whether TF possesses chaperone activity, we analyzed the ability of a tig mutant to survive acid and base stress. While there was no significant decrease for a tig mutant, a ppiB tig double mutant exhibited significant decreases in cell viability after acid and base challenges. We then demonstrated that a ppiB tig double mutant had exacerbated phenotypes in vitro and in vivo, compared to either single mutant. Finally, in vivo immunoprecipitation of epitope-tagged PpiB revealed that PpiB interacted with 4 times the number of proteins when TF was absent from the cell, suggesting that it may be compensating for the loss of TF. Interestingly, the only proteins found to interact with TF were TF itself, fibronectin-binding protein B (FnBPB), and the chaperone protein ClpB. Collectively, these results support the first phenotype for S. aureus TF and demonstrate a greater network of cooperation between chaperone proteins in Staphylococcus aureus. IMPORTANCE S. aureus encodes a large number of virulence factors that aid the bacterium in survival and pathogenesis. These virulence factors have a wide variety of functions; however, they must all be properly secreted in order to be functional. Bacterial chaperone proteins often assist in secretion by trafficking proteins to secretion machinery or assisting in proper protein folding. Here, we report that the S. aureus chaperone TF contributes to biofilm formation and cooperates with the chaperone PpiB to regulate S. aureus virulence processes. These data highlight the first known role for TF in S. aureus and suggest that S. aureus chaperone proteins may be involved in a greater regulatory network in the cell.
Rebecca A. Keogh; Rachel L. Zapf; Andrew Frey; Emily C. Marino; Gillian G. Null; Richard E. Wiemels; Donald L. Holzschu; Lindsey N. Shaw; Ronan K. Carroll. Staphylococcus aureus Trigger Factor Is Involved in Biofilm Formation and Cooperates with the Chaperone PpiB. Journal of Bacteriology 2021, 203, 1 .
AMA StyleRebecca A. Keogh, Rachel L. Zapf, Andrew Frey, Emily C. Marino, Gillian G. Null, Richard E. Wiemels, Donald L. Holzschu, Lindsey N. Shaw, Ronan K. Carroll. Staphylococcus aureus Trigger Factor Is Involved in Biofilm Formation and Cooperates with the Chaperone PpiB. Journal of Bacteriology. 2021; 203 (7):1.
Chicago/Turabian StyleRebecca A. Keogh; Rachel L. Zapf; Andrew Frey; Emily C. Marino; Gillian G. Null; Richard E. Wiemels; Donald L. Holzschu; Lindsey N. Shaw; Ronan K. Carroll. 2021. "Staphylococcus aureus Trigger Factor Is Involved in Biofilm Formation and Cooperates with the Chaperone PpiB." Journal of Bacteriology 203, no. 7: 1.
Regulatory small RNAs (sRNAs) are a class of RNA molecules that are produced in bacterial cells but that typically do not encode proteins. Instead, they perform a variety of critical functions within the cell as RNA. Most bacterial genomes do not include annotations for sRNA genes, and any type of analysis that is performed using a bacterial genome as a reference will therefore overlook data for sRNAs. In this study, we reexamined hundreds of previously generated S. aureus RNA-Seq data sets and reanalyzed them to generate data for sRNAs. To do so, we utilized an updated S. aureus genome annotation file, previously generated by our group, which contains annotations for 303 sRNAs. The data generated (which were previously discarded) shed new light on sRNAs in S. aureus , most of which are unstudied, and highlight certain sRNAs that are likely to play important roles in the cell.
Hailee M. Sorensen; Rebecca A. Keogh; Marcus A. Wittekind; Andrew R. Caillet; Richard E. Wiemels; Elizabeth A. Laner; Ronan K. Carroll. Reading between the Lines: Utilizing RNA-Seq Data for Global Analysis of sRNAs in Staphylococcus aureus. mSphere 2020, 5, 1 .
AMA StyleHailee M. Sorensen, Rebecca A. Keogh, Marcus A. Wittekind, Andrew R. Caillet, Richard E. Wiemels, Elizabeth A. Laner, Ronan K. Carroll. Reading between the Lines: Utilizing RNA-Seq Data for Global Analysis of sRNAs in Staphylococcus aureus. mSphere. 2020; 5 (4):1.
Chicago/Turabian StyleHailee M. Sorensen; Rebecca A. Keogh; Marcus A. Wittekind; Andrew R. Caillet; Richard E. Wiemels; Elizabeth A. Laner; Ronan K. Carroll. 2020. "Reading between the Lines: Utilizing RNA-Seq Data for Global Analysis of sRNAs in Staphylococcus aureus." mSphere 5, no. 4: 1.
Peptidyl-prolyl cis/trans isomerases (PPIases) are enzymes that catalyze the cis-to-trans isomerization around proline bonds, allowing proteins to fold into their correct confirmation. Previously, we identified two PPIase enzymes in Staphylococcus aureus (PpiB and PrsA) that are involved in the regulation of virulence determinants and have shown that PpiB contributes to S. aureus virulence in a murine abscess model of infection. Here, we further examine the role of these PPIases in S. aureus virulence and, in particular, their regulation of hemolytic toxins. Using murine abscess and systemic models of infection, we show that a ppiB mutant in a USA300 background is attenuated for virulence but that a prsA mutant is not. Deletion of the ppiB gene leads to decreased bacterial survival in macrophages and nasal epithelial cells, while there is no significant difference when prsA is deleted. Analysis of culture supernatants reveals that a ppiB mutant strain has reduced levels of the phenol-soluble modulins and that both ppiB and prsA mutants have reduced alpha-toxin activity. Finally, we perform immunoprecipitation to identify cellular targets of PpiB and PrsA. Results suggest a novel role for PpiB in S. aureus protein secretion. Collectively, our results demonstrate that PpiB and PrsA influence S. aureus toxins via distinct mechanisms, and that PpiB but not PrsA contributes to disease.
Rebecca A. Keogh; Rachel L. Zapf; Emily Trzeciak; Gillian G. Null; Richard E. Wiemels; Ronan K. Carroll. Novel Regulation of Alpha-Toxin and the Phenol-Soluble Modulins by Peptidyl-Prolyl cis/trans Isomerase Enzymes in Staphylococcus aureus. Toxins 2019, 11, 343 .
AMA StyleRebecca A. Keogh, Rachel L. Zapf, Emily Trzeciak, Gillian G. Null, Richard E. Wiemels, Ronan K. Carroll. Novel Regulation of Alpha-Toxin and the Phenol-Soluble Modulins by Peptidyl-Prolyl cis/trans Isomerase Enzymes in Staphylococcus aureus. Toxins. 2019; 11 (6):343.
Chicago/Turabian StyleRebecca A. Keogh; Rachel L. Zapf; Emily Trzeciak; Gillian G. Null; Richard E. Wiemels; Ronan K. Carroll. 2019. "Novel Regulation of Alpha-Toxin and the Phenol-Soluble Modulins by Peptidyl-Prolyl cis/trans Isomerase Enzymes in Staphylococcus aureus." Toxins 11, no. 6: 343.
Numerous factors have, to date, been identified as playing a role in the regulation of Agr activity in Staphylococcus aureus , including transcription factors, antisense RNAs, and host elements. Herein we investigated the product of SAUSA300_1984 (termed MroQ), a transmembrane Abi-domain/M79 protease-family protein, as a novel effector of this system.
Stephanie Marroquin; Brittney Gimza; Brooke Tomlinson; Michelle Stein; Andrew Frey; Rebecca A. Keogh; Rachel Zapf; Daniel A. Todd; Nadja B. Cech; Ronan K. Carroll; Lindsey N. Shaw. MroQ Is a Novel Abi-Domain Protein That Influences Virulence Gene Expression in Staphylococcus aureus via Modulation of Agr Activity. Infection and Immunity 2019, 87, e00002-19 .
AMA StyleStephanie Marroquin, Brittney Gimza, Brooke Tomlinson, Michelle Stein, Andrew Frey, Rebecca A. Keogh, Rachel Zapf, Daniel A. Todd, Nadja B. Cech, Ronan K. Carroll, Lindsey N. Shaw. MroQ Is a Novel Abi-Domain Protein That Influences Virulence Gene Expression in Staphylococcus aureus via Modulation of Agr Activity. Infection and Immunity. 2019; 87 (5):e00002-19.
Chicago/Turabian StyleStephanie Marroquin; Brittney Gimza; Brooke Tomlinson; Michelle Stein; Andrew Frey; Rebecca A. Keogh; Rachel Zapf; Daniel A. Todd; Nadja B. Cech; Ronan K. Carroll; Lindsey N. Shaw. 2019. "MroQ Is a Novel Abi-Domain Protein That Influences Virulence Gene Expression in Staphylococcus aureus via Modulation of Agr Activity." Infection and Immunity 87, no. 5: e00002-19.
The alpha phenol-soluble modulins (αPSMs) are among the most potent toxins produced by Staphylococcus aureus . Their biological role during infection has been studied in detail; however, the way they are produced by the bacterial cell is not well understood. In this work, we identify a small RNA molecule called Teg41 that plays an important role in αPSM production by S. aureus . Teg41 positively influences αPSM production. The importance of Teg41 is highlighted by the fact that a strain containing a deletion in the 3′ end of Teg41 produces significantly less αPSMs and is attenuated for virulence in a mouse abscess model of infection. As the search for new therapeutic strategies to combat S. aureus infection proceeds, Teg41 may represent a novel target.
Rachel Zapf; Richard E. Wiemels; Rebecca A. Keogh; Donald L. Holzschu; Kayla M. Howell; Emily Trzeciak; Andrew R. Caillet; Kellie A. King; Samantha A. Selhorst; Michael J. Naldrett; Jeffrey L. Bose; Ronan K. Carroll. The Small RNA Teg41 Regulates Expression of the Alpha Phenol-Soluble Modulins and Is Required for Virulence in Staphylococcus aureus. mBio 2019, 10, e02484-18 .
AMA StyleRachel Zapf, Richard E. Wiemels, Rebecca A. Keogh, Donald L. Holzschu, Kayla M. Howell, Emily Trzeciak, Andrew R. Caillet, Kellie A. King, Samantha A. Selhorst, Michael J. Naldrett, Jeffrey L. Bose, Ronan K. Carroll. The Small RNA Teg41 Regulates Expression of the Alpha Phenol-Soluble Modulins and Is Required for Virulence in Staphylococcus aureus. mBio. 2019; 10 (1):e02484-18.
Chicago/Turabian StyleRachel Zapf; Richard E. Wiemels; Rebecca A. Keogh; Donald L. Holzschu; Kayla M. Howell; Emily Trzeciak; Andrew R. Caillet; Kellie A. King; Samantha A. Selhorst; Michael J. Naldrett; Jeffrey L. Bose; Ronan K. Carroll. 2019. "The Small RNA Teg41 Regulates Expression of the Alpha Phenol-Soluble Modulins and Is Required for Virulence in Staphylococcus aureus." mBio 10, no. 1: e02484-18.
Numerous factors have to date been identified as playing a role in the regulation of Agr activity in S. aureus, including transcription factors, antisense RNAs, and host elements. Herein we investigate the product of SAUSA300_1984 (termed MroQ), a transmembrane Abi-domain/M79 protease-family protein, as a novel effector of this system. Using a USA300 mroQ mutant we observed a drastic reduction in proteolysis, hemolysis and pigmentation that was fully complementable. This appears to result from diminished agr activity, as transcriptional analysis revealed significant decreases in expression of both RNAII and RNAIII in the mroQ mutant. Such effects appear to be direct, rather than indirect, as known agr effectors demonstrated limited alterations in their activity upon mroQ disruption. A comparison of RNA-sequencing datasets for both mroQ and agr mutants reveal a profound overlap in their regulomes, with the majority of factors affected being known virulence determinants. Importantly, the preponderance of alterations in expression were more striking in the agr mutant, indicating that MroQ is necessary, but not sufficient, for Agr function. Mechanism profiling revealed that putative residues for metalloprotease activity within MroQ are required for its Agr controlling effect, however this is not wielded at the level of AgrD processing. Virulence assessment demonstrated that mroQ and agr mutants both exhibited increased formation of renal abscesses, but decreased skin abscess formation, alongside diminished dermonecrosis. Collectively, we present the characterization of a novel agr effector in S. aureus, which would appear to be a direct regulator, potentially functioning via interaction with the AgrC histidine kinase.
Stephanie Marroquin; Brittney D. Gimza; Brooke Tomlinson; Michelle Stein; Andrew Frey; Rebecca A. Keogh; Rachel L Zapf; Daniel A. Todd; Nadja B. Cech; Ronan K. Carroll; Lindsey N. Shaw. MroQ is a Novel Abi-domain Protein That Influences Virulence Gene Expression in Staphylococcus aureus via Modulation of Agr Activity. 2019, 516914 .
AMA StyleStephanie Marroquin, Brittney D. Gimza, Brooke Tomlinson, Michelle Stein, Andrew Frey, Rebecca A. Keogh, Rachel L Zapf, Daniel A. Todd, Nadja B. Cech, Ronan K. Carroll, Lindsey N. Shaw. MroQ is a Novel Abi-domain Protein That Influences Virulence Gene Expression in Staphylococcus aureus via Modulation of Agr Activity. . 2019; ():516914.
Chicago/Turabian StyleStephanie Marroquin; Brittney D. Gimza; Brooke Tomlinson; Michelle Stein; Andrew Frey; Rebecca A. Keogh; Rachel L Zapf; Daniel A. Todd; Nadja B. Cech; Ronan K. Carroll; Lindsey N. Shaw. 2019. "MroQ is a Novel Abi-domain Protein That Influences Virulence Gene Expression in Staphylococcus aureus via Modulation of Agr Activity." , no. : 516914.
The Staphylococcus aureus cyclophilin PpiB is an intracellular peptidyl prolyl cis/trans isomerase (PPIase) that has previously been shown to contribute to secreted nuclease and hemolytic activity. In this study, we investigated the contribution of PpiB to S. aureus virulence.
Rebecca A. Keogh; Rachel Zapf; Richard E. Wiemels; Marcus A. Wittekind; Ronan K. Carroll. The Intracellular Cyclophilin PpiB Contributes to the Virulence of Staphylococcus aureus Independently of Its Peptidyl-Prolyl cis/trans Isomerase Activity. Infection and Immunity 2018, 86, e00379-18 .
AMA StyleRebecca A. Keogh, Rachel Zapf, Richard E. Wiemels, Marcus A. Wittekind, Ronan K. Carroll. The Intracellular Cyclophilin PpiB Contributes to the Virulence of Staphylococcus aureus Independently of Its Peptidyl-Prolyl cis/trans Isomerase Activity. Infection and Immunity. 2018; 86 (11):e00379-18.
Chicago/Turabian StyleRebecca A. Keogh; Rachel Zapf; Richard E. Wiemels; Marcus A. Wittekind; Ronan K. Carroll. 2018. "The Intracellular Cyclophilin PpiB Contributes to the Virulence of Staphylococcus aureus Independently of Its Peptidyl-Prolyl cis/trans Isomerase Activity." Infection and Immunity 86, no. 11: e00379-18.