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Palmer T, Berks BC. The twin-arginine translocation (Tat) system. Curr Biol 2024; 34:R267-R268. [PMID: 38593766 DOI: 10.1016/j.cub.2024.02.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
In this Quick guide, Palmer and Berks introduce the twin-arginine translocation (Tat) systems. Tats are found in a variety of microbes and microbe-derived organelles, and are known to translocate folded substrate proteins across biological membranes.
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Affiliation(s)
- Tracy Palmer
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
| | - Ben C Berks
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
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Rogers AR, Turner EE, Johnson DT, Ellermeier JR. Envelope Stress Activates Expression of the Twin Arginine Translocation (Tat) System in Salmonella. Microbiol Spectr 2022; 10:e0162122. [PMID: 36036643 PMCID: PMC9604234 DOI: 10.1128/spectrum.01621-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 08/16/2022] [Indexed: 12/31/2022] Open
Abstract
The twin arginine translocation system (Tat) is a protein export system that is conserved in bacteria, archaea, and plants. In Gram-negative bacteria, it is required for the export of folded proteins from the cytoplasm to the periplasm. In Salmonella, there are 30 proteins that are predicted substrates of Tat, and among these are enzymes required for anaerobic respiration and peptidoglycan remodeling. We have demonstrated that some conditions that induce bacterial envelope stress activate expression of a ΔtatABC-lacZ fusion in Salmonella enterica serovar Typhimurium. Particularly, the addition of bile salts to the growth medium causes a 3-fold induction of a ΔtatABC-lacZ reporter fusion. Our data demonstrate that this induction is mediated via the phage shock protein (Psp) stress response system protein PspA. Further, we show that deletion of tatABC increases the induction of tatABC expression in bile salts. Indeed, the data suggest significant interaction between PspA and the Tat system in the regulatory response to bile salts. Although we have not identified the precise mechanism of Psp regulation of tatABC, our work shows that PspA is involved in the activation of tatABC expression by bile salts and adds another layer of complexity to the Salmonella response to envelope stress. IMPORTANCE Salmonella species cause an array of diseases in a variety of hosts. This research is significant in showing induction of the Tat system as a defense against periplasmic stress. Understanding the underlying mechanism of this regulation broadens our understanding of the Salmonella stress response, which is critical to the ability of the organism to cause infection.
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Affiliation(s)
- Alexandra R. Rogers
- Department of Microbiology and Immunology, Midwestern University, Glendale, Arizona, USA
| | - Ezekeial E. Turner
- College of Graduate Studies, Midwestern University, Glendale, Arizona, USA
| | - Deauna T. Johnson
- Department of Microbiology and Immunology, Midwestern University, Glendale, Arizona, USA
| | - Jeremy R. Ellermeier
- Department of Microbiology and Immunology, Midwestern University, Glendale, Arizona, USA
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Soh EYC, Smith F, Gimenez MR, Yang L, Vejborg RM, Fletcher M, Halliday N, Bleves S, Heeb S, Cámara M, Givskov M, Hardie KR, Tolker-Nielsen T, Ize B, Williams P. Disruption of the Pseudomonas aeruginosa Tat system perturbs PQS-dependent quorum sensing and biofilm maturation through lack of the Rieske cytochrome bc1 sub-unit. PLoS Pathog 2021; 17:e1009425. [PMID: 34460871 PMCID: PMC8432897 DOI: 10.1371/journal.ppat.1009425] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 09/10/2021] [Accepted: 08/10/2021] [Indexed: 11/18/2022] Open
Abstract
Extracellular DNA (eDNA) is a major constituent of the extracellular matrix of Pseudomonas aeruginosa biofilms and its release is regulated via pseudomonas quinolone signal (PQS) dependent quorum sensing (QS). By screening a P. aeruginosa transposon library to identify factors required for DNA release, mutants with insertions in the twin-arginine translocation (Tat) pathway were identified as exhibiting reduced eDNA release, and defective biofilm architecture with enhanced susceptibility to tobramycin. P. aeruginosa tat mutants showed substantial reductions in pyocyanin, rhamnolipid and membrane vesicle (MV) production consistent with perturbation of PQS-dependent QS as demonstrated by changes in pqsA expression and 2-alkyl-4-quinolone (AQ) production. Provision of exogenous PQS to the tat mutants did not return pqsA, rhlA or phzA1 expression or pyocyanin production to wild type levels. However, transformation of the tat mutants with the AQ-independent pqs effector pqsE restored phzA1 expression and pyocyanin production. Since mutation or inhibition of Tat prevented PQS-driven auto-induction, we sought to identify the Tat substrate(s) responsible. A pqsA::lux fusion was introduced into each of 34 validated P. aeruginosa Tat substrate deletion mutants. Analysis of each mutant for reduced bioluminescence revealed that the primary signalling defect was associated with the Rieske iron-sulfur subunit of the cytochrome bc1 complex. In common with the parent strain, a Rieske mutant exhibited defective PQS signalling, AQ production, rhlA expression and eDNA release that could be restored by genetic complementation. This defect was also phenocopied by deletion of cytB or cytC1. Thus, either lack of the Rieske sub-unit or mutation of cytochrome bc1 genes results in the perturbation of PQS-dependent autoinduction resulting in eDNA deficient biofilms, reduced antibiotic tolerance and compromised virulence factor production. Pseudomonas aeruginosa is a highly adaptable human pathogen responsible for causing chronic biofilm-associated infections. Biofilms are highly refractory to host defences and antibiotics and thus difficult to eradicate. The biofilm extracellular matrix incorporates extracellular DNA (eDNA). This stabilizes biofilm architecture and helps confer tolerance to antibiotics. Since mechanisms that control eDNA release are not well understood, we screened a P. aeruginosa mutant bank for strains with defects in eDNA release and discovered a role for the twin-arginine translocation (Tat) pathway that exports folded proteins across the cytoplasmic membrane. Perturbation of the Tat pathway resulted in defective biofilms susceptible to antibiotic treatment as a consequence of perturbed pseudomonas quinolone (PQS) signalling. This resulted in the failure to produce or release biofilm components including eDNA, phenazines and rhamnolipids as well as microvesicles. Furthermore, we discovered that perturbation of PQS signalling was a consequence of the inability of tat mutants to translocate the Rieske subunit of the cytochrome bc1 complex involved in electron transfer and energy transduction. Given the importance of PQS signalling and the Tat system to virulence and biofilm maturation in P. aeruginosa, our findings underline the potential of the Tat system as a drug target for novel antimicrobial agents.
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Affiliation(s)
- Eliza Ye-Chen Soh
- Biodiscovery Institute, National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Frances Smith
- Biodiscovery Institute, National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Maxime Rémi Gimenez
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires (LISM-UMR7255), Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille University, Marseille, France
| | - Liang Yang
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore
| | - Rebecca Munk Vejborg
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Matthew Fletcher
- Biodiscovery Institute, National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Nigel Halliday
- Biodiscovery Institute, National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Sophie Bleves
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires (LISM-UMR7255), Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille University, Marseille, France
| | - Stephan Heeb
- Biodiscovery Institute, National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Miguel Cámara
- Biodiscovery Institute, National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Michael Givskov
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kim R. Hardie
- Biodiscovery Institute, National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail: (TT-N); (BI); (PW)
| | - Bérengère Ize
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires (LISM-UMR7255), Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille University, Marseille, France
- * E-mail: (TT-N); (BI); (PW)
| | - Paul Williams
- Biodiscovery Institute, National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
- * E-mail: (TT-N); (BI); (PW)
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Ouyang M, Li X, Zhang J, Feng P, Pu H, Kong L, Bai Z, Rong L, Xu X, Chi W, Wang Q, Chen F, Lu C, Shen J, Zhang L. Liquid-Liquid Phase Transition Drives Intra-chloroplast Cargo Sorting. Cell 2020; 180:1144-1159.e20. [PMID: 32169217 DOI: 10.1016/j.cell.2020.02.045] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 01/14/2020] [Accepted: 02/20/2020] [Indexed: 12/21/2022]
Abstract
In eukaryotic cells, organelle biogenesis is pivotal for cellular function and cell survival. Chloroplasts are unique organelles with a complex internal membrane network. The mechanisms of the migration of imported nuclear-encoded chloroplast proteins across the crowded stroma to thylakoid membranes are less understood. Here, we identified two Arabidopsis ankyrin-repeat proteins, STT1 and STT2, that specifically mediate sorting of chloroplast twin arginine translocation (cpTat) pathway proteins to thylakoid membranes. STT1 and STT2 form a unique hetero-dimer through interaction of their C-terminal ankyrin domains. Binding of cpTat substrate by N-terminal intrinsically disordered regions of STT complex induces liquid-liquid phase separation. The multivalent nature of STT oligomer is critical for phase separation. STT-Hcf106 interactions reverse phase separation and facilitate cargo targeting and translocation across thylakoid membranes. Thus, the formation of phase-separated droplets emerges as a novel mechanism of intra-chloroplast cargo sorting. Our findings highlight a conserved mechanism of phase separation in regulating organelle biogenesis.
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Affiliation(s)
- Min Ouyang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Xiaoyi Li
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Jing Zhang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing, China
| | - Peiqiang Feng
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Hua Pu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Lingxi Kong
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing, China
| | - Zechen Bai
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing, China
| | - Liwei Rong
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing, China
| | - Xiumei Xu
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, 85 Minglun Street, Kaifeng 475001, China
| | - Wei Chi
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing, China
| | - Qiang Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, 85 Minglun Street, Kaifeng 475001, China
| | - Fan Chen
- State Key Laboratory of Molecular Developmental Biology, Chinese Academy of Sciences, Beijing 100086, China
| | - Congming Lu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Jianren Shen
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Lixin Zhang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, 85 Minglun Street, Kaifeng 475001, China.
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Tidhar A, Levy Y, Zauberman A, Vagima Y, Gur D, Aftalion M, Israeli O, Chitlaru T, Ariel N, Flashner Y, Zvi A, Mamroud E. Disruption of the NlpD lipoprotein of the plague pathogen Yersinia pestis affects iron acquisition and the activity of the twin-arginine translocation system. PLoS Negl Trop Dis 2019; 13:e0007449. [PMID: 31170147 PMCID: PMC6553720 DOI: 10.1371/journal.pntd.0007449] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 05/08/2019] [Indexed: 11/29/2022] Open
Abstract
We have previously shown that the cell morphogenesis NlpD lipoprotein is essential for virulence of the plague bacteria, Yersinia pestis. To elucidate the role of NlpD in Y. pestis pathogenicity, we conducted a whole-genome comparative transcriptome analysis of the wild-type Y. pestis strain and an nlpD mutant under conditions mimicking early stages of infection. The analysis suggested that NlpD is involved in three phenomena: (i) Envelope stability/integrity evidenced by compensatory up-regulation of the Cpx and Psp membrane stress-response systems in the mutant; (ii) iron acquisition, supported by modulation of iron metabolism genes and by limited growth in iron-deprived medium; (iii) activity of the twin-arginine (Tat) system, which translocates folded proteins across the cytoplasmic membrane. Virulence studies of Y. pestis strains mutated in individual Tat components clearly indicated that the Tat system is central in Y. pestis pathogenicity and substantiated the assumption that NlpD essentiality in iron utilization involves the activity of the Tat system. This study reveals a new role for NlpD in Tat system activity and iron assimilation suggesting a modality by which this lipoprotein is involved in Y. pestis pathogenesis. We have previously shown that the NlpD lipoprotein, which is involved in the regulation of cell morphogenesis, is essential for virulence of the plague bacteria, Yersinia pestis. To uncover the role of NlpD in Y. pestis pathogenicity, we conducted a whole-genome comparative transcriptome analysis as well as phenotypic and virulence evaluation analyses of the nlpD and related mutants. The study reveals a new role for the Y. pestis NlpD lipoprotein in iron assimilation and Tat system activity.
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Affiliation(s)
- Avital Tidhar
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
- * E-mail: (AT); (EM)
| | - Yinon Levy
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Ayelet Zauberman
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Yaron Vagima
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - David Gur
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Moshe Aftalion
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Ofir Israeli
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Theodor Chitlaru
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Naomi Ariel
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Yehuda Flashner
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Anat Zvi
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Emanuelle Mamroud
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
- * E-mail: (AT); (EM)
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Abstract
The inner membrane of Gram-negative bacteria is a ~6 nm thick phospholipid bilayer. It forms a semi-permeable barrier between the cytoplasm and periplasm allowing only regulated export and import of ions, sugar polymers, DNA and proteins. Inner membrane proteins, embedded via hydrophobic transmembrane α-helices, play an essential role in this regulated trafficking: they mediate insertion into the membrane (insertases) or complete crossing of the membrane (translocases) or both. The Gram-negative inner membrane is equipped with a variety of different insertases and translocases. Many of them are specialized, taking care of the export of only a few protein substrates, while others have more general roles. Here, we focus on the three general export/insertion pathways, the secretory (Sec) pathway, YidC and the twin-arginine translocation (TAT) pathway, focusing closely on the Escherichia coli (E. coli) paradigm. We only briefly mention dedicated export pathways found in different Gram-negative bacteria. The Sec system deals with the majority of exported proteins and functions both as a translocase for secretory proteins and an insertase for membrane proteins. The insertase YidC assists the Sec system or operates independently on membrane protein clients. Sec and YidC, in common with most export pathways, require their protein clients to be in soluble non-folded states to fit through the translocation channels and grooves. The TAT pathway is an exception, as it translocates folded proteins, some loaded with prosthetic groups.
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Affiliation(s)
- Jozefien De Geyter
- Laboratory of Molecular Bacteriology, Department of Microbiology and Immunology, Rega Institute for Medical Research, KU Leuven - University of Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Dries Smets
- Laboratory of Molecular Bacteriology, Department of Microbiology and Immunology, Rega Institute for Medical Research, KU Leuven - University of Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Spyridoula Karamanou
- Laboratory of Molecular Bacteriology, Department of Microbiology and Immunology, Rega Institute for Medical Research, KU Leuven - University of Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Anastassios Economou
- Laboratory of Molecular Bacteriology, Department of Microbiology and Immunology, Rega Institute for Medical Research, KU Leuven - University of Leuven, Herestraat 49, 3000, Leuven, Belgium.
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Huang X, Cao L, Qin Z, Li S, Kong W, Liu Y. Tat-Independent Secretion of Polyethylene Terephthalate Hydrolase PETase in Bacillus subtilis 168 Mediated by Its Native Signal Peptide. J Agric Food Chem 2018; 66:13217-13227. [PMID: 30465427 DOI: 10.1021/acs.jafc.8b05038] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Widespread utilization of polyethylene terephthalate (PET) has caused critical environmental pollution. The enzymatic degradation of PET is a promising solution to this problem. In this study, PETase, which exhibits much higher PET-hydrolytic activity than other enzymes, was successfully secreted into extracellular milieu from Bacillus subtilis 168 under the direction of its native signal peptide (named SPPETase). SPPETase is predicted to be a twin-arginine signal peptide. Intriguingly, inactivation of twin-arginine translocation (Tat) complexes improved the secretion amount by 3.8-fold, indicating that PETase was exported via Tat-independent pathway. To the best of our knowledge, this is the first report on the improvement of Tat-independent secretion by inactivating Tat components of B. subtilis 168 in LB medium. Furthermore, PET film degradation assay showed that the secreted PETase was fully active. This study paves the first step to construct an efficient engineered strain for PET degradation.
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Affiliation(s)
- Xin Huang
- School of Life Sciences, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, National Engineering Center for Marine Biotechnology of South China Sea , Sun Yat-Sen University , Guangzhou 510275 , P. R. China
| | - Lichuang Cao
- School of Life Sciences, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, National Engineering Center for Marine Biotechnology of South China Sea , Sun Yat-Sen University , Guangzhou 510275 , P. R. China
| | - Zongmin Qin
- School of Life Sciences, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, National Engineering Center for Marine Biotechnology of South China Sea , Sun Yat-Sen University , Guangzhou 510275 , P. R. China
| | - Shuifeng Li
- School of Life Sciences, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, National Engineering Center for Marine Biotechnology of South China Sea , Sun Yat-Sen University , Guangzhou 510275 , P. R. China
| | - Wei Kong
- School of Life Sciences, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, National Engineering Center for Marine Biotechnology of South China Sea , Sun Yat-Sen University , Guangzhou 510275 , P. R. China
| | - Yuhuan Liu
- School of Life Sciences, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, National Engineering Center for Marine Biotechnology of South China Sea , Sun Yat-Sen University , Guangzhou 510275 , P. R. China
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New CP, Ma Q, Dabney-Smith C. Routing of thylakoid lumen proteins by the chloroplast twin arginine transport pathway. Photosynth Res 2018; 138:289-301. [PMID: 30101370 DOI: 10.1007/s11120-018-0567-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 07/26/2018] [Indexed: 06/08/2023]
Abstract
Thylakoids are complex sub-organellar membrane systems whose role in photosynthesis makes them critical to life. Thylakoids require the coordinated expression of both nuclear- and plastid-encoded proteins to allow rapid response to changing environmental conditions. Transport of cytoplasmically synthesized proteins to thylakoids or the thylakoid lumen is complex; the process involves transport across up to three membrane systems with routing through three aqueous compartments. Protein transport in thylakoids is accomplished by conserved ancestral prokaryotic plasma membrane translocases containing novel adaptations for the sub-organellar location. This review focuses on the evolutionarily conserved chloroplast twin arginine transport (cpTat) pathway. An overview is provided of known aspects of the cpTat components, energy requirements, and mechanisms with a focus on recent discoveries. Some of the most exciting new studies have been in determining the structural architecture of the membrane complex involved in forming the point of passage for the precursor and binding features of the translocase components. The cpTat system is of particular interest because it transports folded protein domains using only the proton motive force for energy. The implications for mechanism of translocation by recent studies focusing on interactions between membrane Tat components and with the translocating precursor will be discussed.
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Affiliation(s)
- Christopher Paul New
- Cellular, Molecular, and Structural Biology Graduate Program, Miami University, Oxford, OH, 45056, USA
| | - Qianqian Ma
- Cellular, Molecular, and Structural Biology Graduate Program, Miami University, Oxford, OH, 45056, USA
| | - Carole Dabney-Smith
- Cellular, Molecular, and Structural Biology Graduate Program, Miami University, Oxford, OH, 45056, USA.
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH, 45056, USA.
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Gimenez MR, Chandra G, Van Overvelt P, Voulhoux R, Bleves S, Ize B. Genome wide identification and experimental validation of Pseudomonas aeruginosa Tat substrates. Sci Rep 2018; 8:11950. [PMID: 30093651 PMCID: PMC6085387 DOI: 10.1038/s41598-018-30393-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 07/30/2018] [Indexed: 11/13/2022] Open
Abstract
In bacteria, the twin-arginine translocation (Tat) pathway allows the export of folded proteins through the inner membrane. Proteins targeted to this system are synthesized with N-terminal signal peptides bearing a conserved twin-arginine motif. The Tat pathway is critical for many bacterial processes including pathogenesis and virulence. However, the full set of Tat substrates is unknown in many bacteria, and the reliability of in silico prediction methods largely uncertain. In this work, we performed a combination of in silico analysis and experimental validation to identify a core set of Tat substrates in the opportunistic pathogen Pseudomonas aeruginosa. In silico analysis predicted 44 putative Tat signal peptides in the P. aeruginosa PA14 proteome. We developed an improved amidase-based Tat reporter assay to show that 33 of these are real Tat signal peptides. In addition, in silico analysis of the full translated genome revealed a Tat candidate with a missassigned start codon. We showed that it is a new periplasmic protein in P. aeruginosa. Altogether we discovered and validated 34 Tat substrates. These show little overlap with Escherichia coli Tat substrates, and functional analysis points to a general role for the P. aeruginosa Tat system in the colonization of environmental niches and pathogenicity.
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Affiliation(s)
- Maxime Rémi Gimenez
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM-UMR7255), Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille Univ., 31 Chemin Joseph Aiguier, CS 70071, 13402 Marseille cedex 09, France
| | - Govind Chandra
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Perrine Van Overvelt
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM-UMR7255), Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille Univ., 31 Chemin Joseph Aiguier, CS 70071, 13402 Marseille cedex 09, France
| | - Romé Voulhoux
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM-UMR7255), Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille Univ., 31 Chemin Joseph Aiguier, CS 70071, 13402 Marseille cedex 09, France
| | - Sophie Bleves
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM-UMR7255), Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille Univ., 31 Chemin Joseph Aiguier, CS 70071, 13402 Marseille cedex 09, France
| | - Bérengère Ize
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM-UMR7255), Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille Univ., 31 Chemin Joseph Aiguier, CS 70071, 13402 Marseille cedex 09, France.
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Zhang C, Xin Y, Wang Y, Guo T, Lu S, Kong J. Identification of a Novel Dye-Decolorizing Peroxidase, EfeB, Translocated by a Twin-Arginine Translocation System in Streptococcus thermophilus CGMCC 7.179. Appl Environ Microbiol 2015; 81:6108-19. [PMID: 26092460 PMCID: PMC4542251 DOI: 10.1128/aem.01300-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 06/14/2015] [Indexed: 11/20/2022] Open
Abstract
Streptococcus thermophilus is a facultative anaerobic bacterium that has the ability to grow and survive in aerobic environments, but the mechanism for this remains unclear. In this study, the efeB gene, encoding a dye-decolorizing peroxidase, was identified in the genome of Streptococcus thermophilus CGMCC 7.179, and purified EfeB was able to decolorize reactive blue 5. Strikingly, genes encoding two components (TatA and TatC) of the twin-arginine translocation (TAT) system were also found in the same operon with the efeB gene. Knocking out efeB or tatC resulted in decreased growth of the strain under aerobic conditions, and complementation of the efeB-deficient strains with the efeB gene enhanced the biomass of the hosts only in the presence of the tatC gene. Moreover, it was proved for both S. thermophilus CGMCC 7.179 and Escherichia coli DE3 that EfeB could be translocated by the TAT system of S. thermophilus. In addition, the transcriptional levels of efeB and tatC increased when the strain was cultured under aerobic conditions. Overall, these results provide the first evidence that EfeB plays a role in protecting cells of S. thermophilus from oxidative stress, with the assistance of the TAT system.
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Affiliation(s)
- Chenchen Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, People's Republic of China
| | - Yongping Xin
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, People's Republic of China
| | - Yue Wang
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, People's Republic of China
| | - Tingting Guo
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, People's Republic of China
| | - Shiyi Lu
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, People's Republic of China
| | - Jian Kong
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, People's Republic of China
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Oertel D, Schmitz S, Freudl R. A TatABC-type Tat translocase is required for unimpaired aerobic growth of Corynebacterium glutamicum ATCC13032. PLoS One 2015; 10:e0123413. [PMID: 25837592 PMCID: PMC4383559 DOI: 10.1371/journal.pone.0123413] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 02/27/2015] [Indexed: 11/30/2022] Open
Abstract
The twin-arginine translocation (Tat) system transports folded proteins across the cytoplasmic membrane of bacteria and the thylakoid membrane of plant chloroplasts. Escherichia coli and other Gram-negative bacteria possess a TatABC-type Tat translocase in which each of the three inner membrane proteins TatA, TatB, and TatC performs a mechanistically distinct function. In contrast, low-GC Gram-positive bacteria, such as Bacillus subtilis, use a TatAC-type minimal Tat translocase in which the TatB function is carried out by a bifunctional TatA. In high-GC Gram-positive Actinobacteria, such as Mycobacterium tuberculosis and Corynebacterium glutamicum, tatA, tatB, and tatC genes can be identified, suggesting that these organisms, just like E. coli, might use TatABC-type Tat translocases as well. However, since contrary to this view a previous study has suggested that C. glutamicum might in fact use a TatAC translocase with TatB only playing a minor role, we reexamined the requirement of TatB for Tat-dependent protein translocation in this microorganism. Under aerobic conditions, the misassembly of the Rieske iron-sulfur protein QcrA was identified as a major reason for the severe growth defect of Tat-defective C. glutamicum mutant strains. Furthermore, our results clearly show that TatB, besides TatA and TatC, is strictly required for unimpaired aerobic growth. In addition, TatB was also found to be essential for the secretion of a heterologous Tat-dependent model protein into the C. glutamicum culture supernatant. Together with our finding that expression of the C. glutamicum TatB in an E. coli ΔtatB mutant strain resulted in the formation of an active Tat translocase, our results clearly indicate that a TatABC translocase is used as the physiologically relevant functional unit for Tat-dependent protein translocation in C. glutamicum and, most likely, also in other TatB-containing Actinobacteria.
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Affiliation(s)
- Dan Oertel
- Institut für Bio- und Geowissenschaften 1, IBG1: Biotechnologie, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Sabrina Schmitz
- Institut für Bio- und Geowissenschaften 1, IBG1: Biotechnologie, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Roland Freudl
- Institut für Bio- und Geowissenschaften 1, IBG1: Biotechnologie, Forschungszentrum Jülich GmbH, Jülich, Germany
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