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Lorenzetti APR, Kusebauch U, Zaramela LS, Wu WJ, de Almeida JPP, Turkarslan S, L. G. de Lomana A, Gomes-Filho JV, Vêncio RZN, Moritz RL, Koide T, Baliga NS. A Genome-Scale Atlas Reveals Complex Interplay of Transcription and Translation in an Archaeon. mSystems 2023; 8:e0081622. [PMID: 36912639 PMCID: PMC10134880 DOI: 10.1128/msystems.00816-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 02/10/2023] [Indexed: 03/14/2023] Open
Abstract
The scale of post-transcriptional regulation and the implications of its interplay with other forms of regulation in environmental acclimation are underexplored for organisms of the domain Archaea. Here, we have investigated the scale of post-transcriptional regulation in the extremely halophilic archaeon Halobacterium salinarum NRC-1 by integrating the transcriptome-wide locations of transcript processing sites (TPSs) and SmAP1 binding, the genome-wide locations of antisense RNAs (asRNAs), and the consequences of RNase_2099C knockout on the differential expression of all genes. This integrated analysis has discovered that 54% of all protein-coding genes in the genome of this haloarchaeon are likely targeted by multiple mechanisms for putative post-transcriptional processing and regulation, with about 20% of genes likely being regulated by combinatorial schemes involving SmAP1, asRNAs, and RNase_2099C. Comparative analysis of mRNA levels (transcriptome sequencing [RNA-Seq]) and protein levels (sequential window acquisition of all theoretical fragment ion spectra mass spectrometry [SWATH-MS]) for 2,579 genes over four phases of batch culture growth in complex medium generated additional evidence for the conditional post-transcriptional regulation of 7% of all protein-coding genes. We demonstrate that post-transcriptional regulation may act to fine-tune specialized and rapid acclimation to stressful environments, e.g., as a switch to turn on gas vesicle biogenesis to promote vertical relocation under anoxic conditions and modulate the frequency of transposition by insertion sequence (IS) elements of the IS200/IS605, IS4, and ISH3 families. Findings from this study are provided as an atlas in a public Web resource (https://halodata.systemsbiology.net). IMPORTANCE While the transcriptional regulation landscape of archaea has been extensively investigated, we currently have limited knowledge about post-transcriptional regulation and its driving mechanisms in this domain of life. In this study, we collected and integrated omics data from multiple sources and technologies to infer post-transcriptionally regulated genes and the putative mechanisms modulating their expression at the protein level in Halobacterium salinarum NRC-1. The results suggest that post-transcriptional regulation may drive environmental acclimation by regulating hallmark biological processes. To foster discoveries by other research groups interested in the topic, we extended our integrated data to the public in the form of an interactive atlas (https://halodata.systemsbiology.net).
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Affiliation(s)
- Alan P. R. Lorenzetti
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
- Institute for Systems Biology, Seattle, Washington, USA
| | | | - Lívia S. Zaramela
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Wei-Ju Wu
- Institute for Systems Biology, Seattle, Washington, USA
| | - João P. P. de Almeida
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | | | | | - José V. Gomes-Filho
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Ricardo Z. N. Vêncio
- Department of Computation and Mathematics, Faculty of Philosophy, Sciences and Letters at Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | | | - Tie Koide
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Nitin S. Baliga
- Institute for Systems Biology, Seattle, Washington, USA
- Department of Biology, University of Washington, Seattle, Washington, USA
- Department of Microbiology, University of Washington, Seattle, Washington, USA
- Molecular and Cellular Biology Program, University of Washington, Seattle, Washington, USA
- Lawrence Berkeley National Lab, Berkeley, California, USA
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2
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Born J, Weitzel K, Suess B, Pfeifer F. A Synthetic Riboswitch to Regulate Haloarchaeal Gene Expression. Front Microbiol 2021; 12:696181. [PMID: 34211452 PMCID: PMC8241225 DOI: 10.3389/fmicb.2021.696181] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 05/21/2021] [Indexed: 11/13/2022] Open
Abstract
In recent years, synthetic riboswitches have become increasingly important to construct genetic circuits in all three domains of life. In bacteria, synthetic translational riboswitches are often employed that modulate gene expression by masking the Shine-Dalgarno (SD) sequence in the absence or presence of a cognate ligand. For (halo-)archaeal translation, a SD sequence is not strictly required. The application of synthetic riboswitches in haloarchaea is therefore limited so far, also because of the molar intracellular salt concentrations found in these microbes. In this study, we applied synthetic theophylline-dependent translational riboswitches in the archaeon Haloferax volcanii. The riboswitch variants A through E and E∗ were chosen since they not only mask the SD sequence but also the AUG start codon by forming a secondary structure in the absence of the ligand theophylline. Upon addition of the ligand, the ribosomal binding site and start codon become accessible for translation initiation. Riboswitch E mediated a dose-dependent, up to threefold activation of the bgaH reporter gene expression. Raising the salt concentration of the culture media from 3 to 4 M NaCl resulted in a 12-fold increase in the switching capacity of riboswitch E, and switching activity increased up to 26-fold when the cultivating temperature was reduced from 45 to 30°C. To construct a genetic circuit, riboswitch E was applied to regulate the synthesis of the transcriptional activator GvpE allowing a dose-dependent activation of the mgfp6 reporter gene under P pA promoter control.
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Affiliation(s)
| | | | - Beatrix Suess
- Synthetic RNA Biology, Department of Biology, Technical University Darmstadt, Darmstadt, Germany.,Centre of Synthetic Biology, Technical University Darmstadt, Darmstadt, Germany
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Zhou S, Xiang H, Liu JL. CTP synthase forms cytoophidia in archaea. J Genet Genomics 2020; 47:213-223. [DOI: 10.1016/j.jgg.2020.03.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 03/12/2020] [Accepted: 03/18/2020] [Indexed: 12/14/2022]
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Born J, Pfeifer F. Improved GFP Variants to Study Gene Expression in Haloarchaea. Front Microbiol 2019; 10:1200. [PMID: 31191505 PMCID: PMC6550001 DOI: 10.3389/fmicb.2019.01200] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 05/13/2019] [Indexed: 12/04/2022] Open
Abstract
The study of promoter activities in haloarchaea is carried out exclusively using enzymes as reporters. An alternative reporter is the gene encoding the Green Fluorescent Protein (GFP), a simple and fast tool for investigating promoter strengths. However, the GFP variant smRS-GFP, used to analyze protein stabilities in haloarchaea, is not suitable to quantify weak promoter activities, since the fluorescence signal is too low. We enhanced the fluorescence of smRS-GFP 3.3-fold by introducing ten amino acid substitutions, resulting in mGFP6. Using mGFP6 as reporter, we studied six haloarchaeal promoters exhibiting different promoter strengths. The strongest activity was observed with the housekeeping promoters Pfdx of the ferredoxin gene and P2 of the ribosomal 16S rRNA gene. Much lower activities were determined for the promoters of the p-vac region driving the expression of gas vesicle protein (gvp) genes in Halobacterium salinarum PHH1. The basal promoter strength dropped in the order PpA, PpO > PpF, PpD. All promoters showed a growth-dependent activity pattern. The GvpE-induced activities of PpA and PpD were high, but lower compared to the Pfdx or P2 promoter activities. The mGFP6 reporter was also used to investigate the regulatory effects of 5′-untranslated regions (5′-UTRs) of three different gvp mRNAs. A deletion of the 5′-UTR always resulted in an increased expression, implying a negative effect of the 5′-UTRs on translation. Our experiments confirmed mGFP6 as simple, fast and sensitive reporter to study gene expression in haloarchaea.
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Affiliation(s)
- Johannes Born
- Microbiology and Archaea, Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
| | - Felicitas Pfeifer
- Microbiology and Archaea, Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
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Liao Y, Williams TJ, Walsh JC, Ji M, Poljak A, Curmi PMG, Duggin IG, Cavicchioli R. Developing a genetic manipulation system for the Antarctic archaeon, Halorubrum lacusprofundi: investigating acetamidase gene function. Sci Rep 2016; 6:34639. [PMID: 27708407 PMCID: PMC5052560 DOI: 10.1038/srep34639] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 09/16/2016] [Indexed: 01/04/2023] Open
Abstract
No systems have been reported for genetic manipulation of cold-adapted Archaea. Halorubrum lacusprofundi is an important member of Deep Lake, Antarctica (~10% of the population), and is amendable to laboratory cultivation. Here we report the development of a shuttle-vector and targeted gene-knockout system for this species. To investigate the function of acetamidase/formamidase genes, a class of genes not experimentally studied in Archaea, the acetamidase gene, amd3, was disrupted. The wild-type grew on acetamide as a sole source of carbon and nitrogen, but the mutant did not. Acetamidase/formamidase genes were found to form three distinct clades within a broad distribution of Archaea and Bacteria. Genes were present within lineages characterized by aerobic growth in low nutrient environments (e.g. haloarchaea, Starkeya) but absent from lineages containing anaerobes or facultative anaerobes (e.g. methanogens, Epsilonproteobacteria) or parasites of animals and plants (e.g. Chlamydiae). While acetamide is not a well characterized natural substrate, the build-up of plastic pollutants in the environment provides a potential source of introduced acetamide. In view of the extent and pattern of distribution of acetamidase/formamidase sequences within Archaea and Bacteria, we speculate that acetamide from plastics may promote the selection of amd/fmd genes in an increasing number of environmental microorganisms.
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Affiliation(s)
- Y Liao
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - T J Williams
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - J C Walsh
- School of Physics, The University of New South Wales, Sydney, New South Wales, 2052, Australia.,The ithree institute, University of Technology Sydney, Broadway, New South Wales, 2007, Australia
| | - M Ji
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - A Poljak
- Bioanalytical Mass Spectrometry Facility, The University of New South Wales, Sydney, New South Wales, Australia
| | - P M G Curmi
- School of Physics, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - I G Duggin
- The ithree institute, University of Technology Sydney, Broadway, New South Wales, 2007, Australia
| | - R Cavicchioli
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, 2052, Australia
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Haloarchaea and the formation of gas vesicles. Life (Basel) 2015; 5:385-402. [PMID: 25648404 PMCID: PMC4390858 DOI: 10.3390/life5010385] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 01/19/2015] [Accepted: 01/26/2015] [Indexed: 11/17/2022] Open
Abstract
Halophilic Archaea (Haloarchaea) thrive in salterns containing sodium chloride concentrations up to saturation. Many Haloarchaea possess genes encoding gas vesicles, but only a few species, such as Halobacterium salinarum and Haloferax mediterranei, produce these gas-filled, proteinaceous nanocompartments. Gas vesicles increase the buoyancy of cells and enable them to migrate vertically in the water body to regions with optimal conditions. Their synthesis depends on environmental factors, such as light, oxygen supply, temperature and salt concentration. Fourteen gas vesicle protein (gvp) genes are involved in their formation, and regulation of gvp gene expression occurs at the level of transcription, including the two regulatory proteins, GvpD and GvpE, but also at the level of translation. The gas vesicle wall is solely formed of proteins with the two major components, GvpA and GvpC, and seven additional accessory proteins are also involved. Except for GvpI and GvpH, all of these are required to form the gas permeable wall. The applications of gas vesicles include their use as an antigen presenter for viral or pathogen proteins, but also as a stable ultrasonic reporter for biomedical purposes.
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Tavlaridou S, Winter K, Pfeifer F. The accessory gas vesicle protein GvpM of haloarchaea and its interaction partners during gas vesicle formation. Extremophiles 2014; 18:693-706. [PMID: 24846741 DOI: 10.1007/s00792-014-0650-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 04/27/2014] [Indexed: 11/29/2022]
Abstract
Gas vesicles consist predominantly of the hydrophobic GvpA and GvpC, and the accessory proteins GvpF through GvpM are required in minor amounts during formation. GvpM and its putative interaction partners were investigated. GvpM interacted with GvpH, GvpJ and GvpL, but not with GvpG. Interactions were also observed in vivo in Haloferax volcanii transformants using Gvp fusions to the green fluorescent protein smGFP. Cells producing the hydrophobic M(GF)P contained a single fluorescent aggregate per cell, whereas cells containing L(GFP) or H(GFP) were fully fluorescent. The soluble L(GFP) formed stable co-aggregates with GvpM in L(GFP)M transformants, but the presence of GvpH resulted in the absence of M(GF)P foci in HM(GFP) transformants. Substitution- and deletion mutants of GvpM determined functionally important amino acids (aa). Substitution of a polar by a non-polar aa in the N-terminal region of GvpM had no effect, whereas a substitution of a non-polar by a polar aa in this region inhibited gas vesicle formation in transformants. Substitutions in region 44-48 of GvpM strongly reduced the number of gas vesicles, and deletions at the N-terminus resulted in Vac(-) transformants. Gas vesicle morphology was not affected by any mutation, implying that GvpM is required during initial stages of gas vesicle assembly.
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Affiliation(s)
- Stella Tavlaridou
- Mikrobiologie und Archaea, Fachbereich Biologie, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287, Darmstadt, Germany
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