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Filipe Alípio A, Bárria C, Pobre V, Rita Matos A, Carrera Prata S, Amblar M, Maria Arraiano C, Domingues S. RNase R Affects the Level of Fatty Acid Biosynthesis Transcripts Leading to Changes in Membrane Fluidity. J Mol Biol 2024:168711. [PMID: 39019106 DOI: 10.1016/j.jmb.2024.168711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 07/10/2024] [Accepted: 07/10/2024] [Indexed: 07/19/2024]
Abstract
Previous studies on RNase R have highlighted significant effects of this ribonuclease in several processes of Streptococcus pneumoniae biology. In this work we show that elimination of RNase R results in overexpression of most of genes encoding the components of type II fatty acid biosynthesis (FASII) cluster. We demonstrate that RNase R is implicated in the turnover of most of transcripts from this pathway, affecting the outcome of the whole FASII cluster, and ultimately leading to changes in the membrane fatty acid composition. Our results show that the membrane of the deleted strain contains higher proportion of unsaturated and long-chained fatty acids than the membrane of the wild type strain. These alterations render the RNase R mutant more prone to membrane lipid peroxidation and are likely the reason for the increased sensitivity of this strain to detergent lysis and to the action of the bacteriocin nisin. Reprogramming of membrane fluidity is an adaptative cell response crucial for bacterial survival in constantly changing environmental conditions. The data presented here is suggestive of a role for RNase R in the composition of S. pneumoniae membrane , with strong impact on pneumococci adaptation to different stress situations.
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Affiliation(s)
- André Filipe Alípio
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Cátia Bárria
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
| | - Vânia Pobre
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Ana Rita Matos
- BioISI - Biosystems and Integrative Sciences Institute, Environmental and Molecular Plant Physiology Laboratory, Departamento de Biologia Vegetal, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Sara Carrera Prata
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Mónica Amblar
- Unidad de Patología Molecular del Neumococo, Centro Nacional de Microbiología, Instituto de Salud Carlos III. Majadahonda, Madrid 28220, Spain
| | - Cecília Maria Arraiano
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Susana Domingues
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
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Yasui Y, Hirayama S, Hiyoshi T, Isono T, Domon H, Maekawa T, Tabeta K, Terao Y. The Pneumococcal Protein SufC Binds to Host Plasminogen and Promotes Its Conversion into Plasmin. Microorganisms 2023; 11:2969. [PMID: 38138113 PMCID: PMC10745484 DOI: 10.3390/microorganisms11122969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 12/08/2023] [Accepted: 12/11/2023] [Indexed: 12/24/2023] Open
Abstract
Streptococcus pneumoniae causes otitis media, sinusitis, and serious diseases such as pneumonia and bacteremia. However, the in vivo dynamics of S. pneumoniae infections and disease severity are not fully understood. In this study, we investigated pneumococcal proteins detected in the bronchoalveolar lavage fluid of an S. pneumoniae-infected mouse, which were assumed to be expressed during infection. Analysis of three proteins with unknown infection-related functions revealed that recombinant Fe-S cluster assembly ATP-binding protein (SufC) binds to the host plasminogen and promotes its conversion into plasmin. SufC was detected in the bacterial cell-surface protein fraction, but it had no extracellular secretory signal. This study suggests that S. pneumoniae releases SufC extracellularly through LytA-dependent autolysis, binding to the bacterial cell surface and host plasminogen and promoting its conversion into plasmin. The recruitment of plasmin by S. pneumoniae is considered useful for bacterial survival and spread, and SufC is suggested to facilitate this process.
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Affiliation(s)
- Yoshihito Yasui
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8514, Japan
- Division of Periodontology, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8514, Japan
| | - Satoru Hirayama
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8514, Japan
| | - Takumi Hiyoshi
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8514, Japan
- Division of Periodontology, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8514, Japan
- Center for Advanced Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8514, Japan
| | - Toshihito Isono
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8514, Japan
| | - Hisanori Domon
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8514, Japan
- Center for Advanced Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8514, Japan
| | - Tomoki Maekawa
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8514, Japan
- Division of Periodontology, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8514, Japan
- Center for Advanced Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8514, Japan
| | - Koichi Tabeta
- Division of Periodontology, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8514, Japan
| | - Yutaka Terao
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8514, Japan
- Center for Advanced Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8514, Japan
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RNase R, a New Virulence Determinant of Streptococcus pneumoniae. Microorganisms 2022; 10:microorganisms10020317. [PMID: 35208772 PMCID: PMC8875335 DOI: 10.3390/microorganisms10020317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/20/2022] [Accepted: 01/25/2022] [Indexed: 11/30/2022] Open
Abstract
Pneumococcal infections have increasingly high mortality rates despite the availability of vaccines and antibiotics. Therefore, the identification of new virulence determinants and the understanding of the molecular mechanisms behind pathogenesis have become of paramount importance in the search of new targets for drug development. The exoribonuclease RNase R has been involved in virulence in a growing number of pathogens. In this work, we used Galleria mellonella as an infection model to demonstrate that the presence of RNase R increases the pneumococcus virulence. Larvae infected with the RNase R mutant show an increased expression level of antimicrobial peptides. Furthermore, they have a lower bacterial load in the hemolymph in the later stages of infection, leading to a higher survival rate of the larvae. Interestingly, pneumococci expressing RNase R show a sudden drop in bacterial numbers immediately after infection, resembling the eclipse phase observed after intravenous inoculation in mice. Concomitantly, we observed a lower number of mutant bacteria inside larval hemocytes and a higher susceptibility to oxidative stress when compared to the wild type. Together, our results indicate that RNase R is involved in the ability of pneumococci to evade the host immune response, probably by interfering with internalization and/or replication inside the larval hemocytes.
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Acebo P, Herranz C, Espenberger LB, Gómez-Sanz A, Terrón MC, Luque D, Amblar M. A Small Non-Coding RNA Modulates Expression of Pilus-1 Type in Streptococcus pneumoniae. Microorganisms 2021; 9:microorganisms9091883. [PMID: 34576778 PMCID: PMC8465756 DOI: 10.3390/microorganisms9091883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/30/2021] [Accepted: 09/01/2021] [Indexed: 11/16/2022] Open
Abstract
Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide, and about 30% of the pneumococcal clinical isolates show type I pili-like structures. These long proteinaceous polymers extending from the bacterial surface are encoded by pilus islet 1 and play major roles in adhesion and host colonization. Pili expression is bistable and is controlled by the transcriptional activator RlrA. In this work, we demonstrate that the previously identified small noncoding RNA srn135 also participates in pilus regulation. Our findings show that srn135 is generated upon processing of the 5′-UTR region of rrgA messenger and its deletion prevents the synthesis of RrgA, the main pili adhesin. Moreover, overexpression of srn135 increases the expression of all pili genes and rises the percentage of piliated bacteria within a clonal population. This regulation is mediated by the stabilization of rlrA mRNA since higher levels of srn135 increase its half-life to 165%. Our findings suggest that srn135 has a dual role in pilus expression acting both in cis- (on the RrgA levels) and in trans- (modulating the levels of RlrA) and contributes to the delicate balance between pili expressing and non-expressing bacteria.
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Affiliation(s)
- Paloma Acebo
- Unidad de Patología Molecular del Neumococo, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, 28220 Madrid, Spain; (P.A.); (C.H.); (L.B.E.); (A.G.-S.)
| | - Cristina Herranz
- Unidad de Patología Molecular del Neumococo, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, 28220 Madrid, Spain; (P.A.); (C.H.); (L.B.E.); (A.G.-S.)
| | - Lucas Bernal Espenberger
- Unidad de Patología Molecular del Neumococo, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, 28220 Madrid, Spain; (P.A.); (C.H.); (L.B.E.); (A.G.-S.)
| | - Alicia Gómez-Sanz
- Unidad de Patología Molecular del Neumococo, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, 28220 Madrid, Spain; (P.A.); (C.H.); (L.B.E.); (A.G.-S.)
| | - María Carmen Terrón
- Unidad de Microscopia Electrónica y Confocal, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, 28220 Madrid, Spain; (M.C.T.); (D.L.)
| | - Daniel Luque
- Unidad de Microscopia Electrónica y Confocal, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, 28220 Madrid, Spain; (M.C.T.); (D.L.)
| | - Mónica Amblar
- Unidad de Patología Molecular del Neumococo, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, 28220 Madrid, Spain; (P.A.); (C.H.); (L.B.E.); (A.G.-S.)
- Correspondence:
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