1
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Royzenblat SK, Freddolino L. Spatio-temporal organization of the E. coli chromosome from base to cellular length scales. EcoSal Plus 2024; 12:eesp00012022. [PMID: 38864557 PMCID: PMC11636183 DOI: 10.1128/ecosalplus.esp-0001-2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 04/17/2024] [Indexed: 06/13/2024]
Abstract
Escherichia coli has been a vital model organism for studying chromosomal structure, thanks, in part, to its small and circular genome (4.6 million base pairs) and well-characterized biochemical pathways. Over the last several decades, we have made considerable progress in understanding the intricacies of the structure and subsequent function of the E. coli nucleoid. At the smallest scale, DNA, with no physical constraints, takes on a shape reminiscent of a randomly twisted cable, forming mostly random coils but partly affected by its stiffness. This ball-of-spaghetti-like shape forms a structure several times too large to fit into the cell. Once the physiological constraints of the cell are added, the DNA takes on overtwisted (negatively supercoiled) structures, which are shaped by an intricate interplay of many proteins carrying out essential biological processes. At shorter length scales (up to about 1 kb), nucleoid-associated proteins organize and condense the chromosome by inducing loops, bends, and forming bridges. Zooming out further and including cellular processes, topological domains are formed, which are flanked by supercoiling barriers. At the megabase-scale both large, highly self-interacting regions (macrodomains) and strong contacts between distant but co-regulated genes have been observed. At the largest scale, the nucleoid forms a helical ellipsoid. In this review, we will explore the history and recent advances that pave the way for a better understanding of E. coli chromosome organization and structure, discussing the cellular processes that drive changes in DNA shape, and what contributes to compaction and formation of dynamic structures, and in turn how bacterial chromatin affects key processes such as transcription and replication.
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Affiliation(s)
- Sonya K. Royzenblat
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Lydia Freddolino
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Computational Medicine & Bioinformatics, University of Michigan Medical School, Ann Arbor, Michigan, USA
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2
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Shang W, Lichtenberg E, Mlesnita AM, Wilde A, Koch HG. The contribution of mRNA targeting to spatial protein localization in bacteria. FEBS J 2024; 291:4639-4659. [PMID: 38226707 DOI: 10.1111/febs.17054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/27/2023] [Accepted: 01/08/2024] [Indexed: 01/17/2024]
Abstract
About 30% of all bacterial proteins execute their function outside of the cytosol and must be inserted into or translocated across the cytoplasmic membrane. This requires efficient targeting systems that recognize N-terminal signal sequences in client proteins and deliver them to protein transport complexes in the membrane. While the importance of these protein transport machineries for the spatial organization of the bacterial cell is well documented in multiple studies, the contribution of mRNA targeting and localized translation to protein transport is only beginning to emerge. mRNAs can exhibit diverse subcellular localizations in the bacterial cell and can accumulate at sites where new protein is required. This is frequently observed for mRNAs encoding membrane proteins, but the physiological importance of membrane enrichment of mRNAs and the consequences it has for the insertion of the encoded protein have not been explored in detail. Here, we briefly highlight some basic concepts of signal sequence-based protein targeting and describe in more detail strategies that enable the monitoring of mRNA localization in bacterial cells and potential mechanisms that route mRNAs to particular positions within the cell. Finally, we summarize some recent developments that demonstrate that mRNA targeting and localized translation can sustain membrane protein insertion under stress conditions when the protein-targeting machinery is compromised. Thus, mRNA targeting likely acts as a back-up strategy and complements the canonical signal sequence-based protein targeting.
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Affiliation(s)
- Wenkang Shang
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, Albert-Ludwigs University Freiburg, Germany
- Faculty of Biology, Albert-Ludwigs University Freiburg, Germany
| | | | - Andreea Mihaela Mlesnita
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, Albert-Ludwigs University Freiburg, Germany
| | - Annegret Wilde
- Faculty of Biology, Albert-Ludwigs University Freiburg, Germany
| | - Hans-Georg Koch
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, Albert-Ludwigs University Freiburg, Germany
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3
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Sett A, Maiti PK, Garg K, Hussain A, Saini S, Pandey S, Pathania R. 'GGFGGQ' repeats in Hfq of Acinetobacter baumannii are essential for nutrient utilization and virulence. J Biol Chem 2024; 300:107895. [PMID: 39424139 PMCID: PMC11617691 DOI: 10.1016/j.jbc.2024.107895] [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: 08/15/2024] [Revised: 09/20/2024] [Accepted: 10/10/2024] [Indexed: 10/21/2024] Open
Abstract
The nosocomial pathogen Acinetobacter baumannii is known for causing lung and soft tissue infections in immunocompromised hosts. Its ability to adapt to various environments through post-transcriptional gene regulation is key to its success. Central to this regulation is the RNA chaperone Hfq, which facilitates interactions between mRNA targets and their small RNA partners through a Sm-core domain. Notably, the A. baumannii Hfq protein has a uniquely long C-terminal domain with "GGFGGQ" amino acid repeats and an acidic amino acid-rich C-terminal tip (C-tip). Previous research has shown the importance of the intact C-terminal domain for Hfq's functionality. Given the significance of the C-tip in Escherichia coli Hfq, we examined the pathophysiological roles of the redundant 'GGFGGQ' repeats along with the C-tip of A. baumannii Hfq. We constructed several variations of Hfq protein with fewer 'GGFGGQ' repeats while preserving the C-tip and variants with altered C-tip amino acid composition. We then studied their RNA interaction abilities and assessed the pathophysiological fitness and virulence of genome-complemented A. baumannii mutants. Our findings reveal that the redundancy of the 'GGFGGQ' repeats is crucial for Hfq's role in pathophysiological fitness and negatively impacts A. baumannii's virulence in a murine lung infection model. In addition, C-tip mutants exhibited a negative effect on both fitness and virulence, however, to a lesser extent than the other variants. These results underscore the importance of 'GGFGGQ' redundancy and acidic residues in Hfq's ribo-regulation and autoregulation, suggesting their critical role in establishing regulatory networks.
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Affiliation(s)
- Abhiroop Sett
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, Uttarakhand, India
| | - Pulak Kumar Maiti
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, Uttarakhand, India
| | - Kritika Garg
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, Uttarakhand, India
| | - Arsalan Hussain
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, Uttarakhand, India
| | - Snehlata Saini
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, Uttarakhand, India
| | - Shivam Pandey
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, Uttarakhand, India
| | - Ranjana Pathania
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, Uttarakhand, India; Centre of Excellence in Disaster Mitigation and Management, Indian Institute of Technology, Roorkee, Uttarakhand, India.
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4
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Moreira S, Chyou TY, Wade J, Brown C. Diversification of the Rho transcription termination factor in bacteria. Nucleic Acids Res 2024; 52:8979-8997. [PMID: 38966992 PMCID: PMC11347177 DOI: 10.1093/nar/gkae582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 06/17/2024] [Accepted: 06/24/2024] [Indexed: 07/06/2024] Open
Abstract
Correct termination of transcription is essential for gene expression. In bacteria, factor-dependent termination relies on the Rho factor, that classically has three conserved domains. Some bacteria also have a functional insertion region. However, the variation in Rho structure among bacteria has not been analyzed in detail. This study determines the distribution, sequence conservation, and predicted features of Rho factors with diverse domain architectures by analyzing 2730 bacterial genomes. About half (49.8%) of the species analyzed have the typical Escherichia coli like Rho while most of the other species (39.8%) have diverse, atypical forms of Rho. Besides conservation of the main domains, we describe a duplicated RNA-binding domain present in specific species and novel variations in the bicyclomycin binding pocket. The additional regions observed in Rho proteins exhibit remarkable diversity. Commonly, however, they have exceptional amino acid compositions and are predicted to be intrinsically disordered, to undergo phase separation, or have prion-like behavior. Phase separation has recently been shown to play roles in Rho function and bacterial fitness during harsh conditions in one species and this study suggests a more widespread role. In conclusion, diverse atypical Rho factors are broadly distributed among bacteria, suggesting additional cellular roles.
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Affiliation(s)
- Sofia M Moreira
- Department of Biochemistry, University of Otago, Dunedin, Otago 9054, New Zealand
| | - Te-yuan Chyou
- Department of Biochemistry, University of Otago, Dunedin, Otago 9054, New Zealand
| | - Joseph T Wade
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY 12222, USA
| | - Chris M Brown
- Department of Biochemistry, University of Otago, Dunedin, Otago 9054, New Zealand
- Genetics Otago, University of Otago, Dunedin, Otago 9054, New Zealand
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5
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Sasazawa M, Tomares DT, Childers WS, Saurabh S. Biomolecular condensates as stress sensors and modulators of bacterial signaling. PLoS Pathog 2024; 20:e1012413. [PMID: 39146259 PMCID: PMC11326607 DOI: 10.1371/journal.ppat.1012413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2024] Open
Abstract
Microbes exhibit remarkable adaptability to environmental fluctuations. Signaling mechanisms, such as two-component systems and secondary messengers, have long been recognized as critical for sensing and responding to environmental cues. However, recent research has illuminated the potential of a physical adaptation mechanism in signaling-phase separation, which may represent a ubiquitous mechanism for compartmentalizing biochemistry within the cytoplasm in the context of bacteria that frequently lack membrane-bound organelles. This review considers the broader prospect that phase separation may play critical roles as rapid stress sensing and response mechanisms within pathogens. It is well established that weak multivalent interactions between disordered regions, coiled-coils, and other structured domains can form condensates via phase separation and be regulated by specific environmental parameters in some cases. The process of phase separation itself acts as a responsive sensor, influenced by changes in protein concentration, posttranslational modifications, temperature, salts, pH, and oxidative stresses. This environmentally triggered phase separation can, in turn, regulate the functions of recruited biomolecules, providing a rapid response to stressful conditions. As examples, we describe biochemical pathways organized by condensates that are essential for cell physiology and exhibit signaling features. These include proteins that organize and modify the chromosome (Dps, Hu, SSB), regulate the decay, and modification of RNA (RNase E, Hfq, Rho, RNA polymerase), those involved in signal transduction (PopZ, PodJ, and SpmX) and stress response (aggresomes and polyphosphate granules). We also summarize the potential of proteins within pathogens to function as condensates and the potential and challenges in targeting biomolecular condensates for next-generation antimicrobial therapeutics. Together, this review illuminates the emerging significance of biomolecular condensates in microbial signaling, stress responses, and regulation of cell physiology and provides a framework for microbiologists to consider the function of biomolecular condensates in microbial adaptation and response to diverse environmental conditions.
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Affiliation(s)
- Moeka Sasazawa
- Department of Chemistry, New York University, New York, New York, United States of America
| | - Dylan T Tomares
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - W Seth Childers
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Saumya Saurabh
- Department of Chemistry, New York University, New York, New York, United States of America
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6
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Nandana V, Al-Husini N, Vaishnav A, Dilrangi KH, Schrader JM. Caulobacter crescentus RNase E condensation contributes to autoregulation and fitness. Mol Biol Cell 2024; 35:ar104. [PMID: 38865176 PMCID: PMC11321048 DOI: 10.1091/mbc.e23-12-0493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 05/29/2024] [Accepted: 06/03/2024] [Indexed: 06/13/2024] Open
Abstract
RNase E is the most common RNA decay nuclease in bacteria, setting the global mRNA decay rate and scaffolding formation of the RNA degradosome complex and BR-bodies. To properly set the global mRNA decay rate, RNase E from Escherichia coli and neighboring γ-proteobacteria were found to autoregulate RNase E levels via the decay of its mRNA's 5' untranslated region (UTR). While the 5' UTR is absent from other groups of bacteria in the Rfam database, we identified that the α-proteobacterium Caulobacter crescentus RNase E contains a similar 5' UTR structure that promotes RNase E autoregulation. In both bacteria, the C-terminal intrinsically disordered region (IDR) of RNase E is required for proper autoregulation to occur, and this IDR is also necessary and sufficient for RNase E to phase-separate, generating BR-bodies. Using in vitro purified RNase E, we find that the IDR's ability to promote phase separation correlates with enhanced 5' UTR cleavage, suggesting that phase separation of RNase E with the 5' UTR enhances autoregulation. Finally, using growth competition experiments, we find that a strain capable of autoregulation rapidly outcompetes a strain with a 5' UTR mutation that cannot autoregulate, suggesting autoregulation promotes optimal cellular fitness.
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Affiliation(s)
- Vidhyadhar Nandana
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202
| | - Nadra Al-Husini
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202
| | - Arti Vaishnav
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202
| | | | - Jared M. Schrader
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202
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7
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Zhou HX, Kota D, Qin S, Prasad R. Fundamental Aspects of Phase-Separated Biomolecular Condensates. Chem Rev 2024; 124:8550-8595. [PMID: 38885177 PMCID: PMC11260227 DOI: 10.1021/acs.chemrev.4c00138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/20/2024]
Abstract
Biomolecular condensates, formed through phase separation, are upending our understanding in much of molecular, cell, and developmental biology. There is an urgent need to elucidate the physicochemical foundations of the behaviors and properties of biomolecular condensates. Here we aim to fill this need by writing a comprehensive, critical, and accessible review on the fundamental aspects of phase-separated biomolecular condensates. We introduce the relevant theoretical background, present the theoretical basis for the computation and experimental measurement of condensate properties, and give mechanistic interpretations of condensate behaviors and properties in terms of interactions at the molecular and residue levels.
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Affiliation(s)
- Huan-Xiang Zhou
- Department of Chemistry, University of Illinois Chicago, Chicago, Illinois 60607, USA
- Department of Physics, University of Illinois Chicago, Chicago, Illinois 60607, USA
| | - Divya Kota
- Department of Chemistry, University of Illinois Chicago, Chicago, Illinois 60607, USA
| | - Sanbo Qin
- Department of Chemistry, University of Illinois Chicago, Chicago, Illinois 60607, USA
| | - Ramesh Prasad
- Department of Chemistry, University of Illinois Chicago, Chicago, Illinois 60607, USA
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8
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Guo D, Xiong Y, Fu B, Sha Z, Li B, Wu H. Liquid-Liquid phase separation in bacteria. Microbiol Res 2024; 281:127627. [PMID: 38262205 DOI: 10.1016/j.micres.2024.127627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 12/16/2023] [Accepted: 01/15/2024] [Indexed: 01/25/2024]
Abstract
Cells are the essential building blocks of living organisms, responsible for carrying out various biochemical reactions and performing specific functions. In eukaryotic cells, numerous membrane organelles have evolved to facilitate these processes by providing specific spatial locations. In recent years, it has also been discovered that membraneless organelles play a crucial role in the subcellular organization of bacteria, which are single-celled prokaryotic microorganisms characterized by their simple structure and small size. These membraneless organelles in bacteria have been found to undergo Liquid-Liquid phase separation (LLPS), a molecular mechanism that allows for their assembly. Through extensive research, the occurrence of LLPS and its role in the spatial organization of bacteria have been better understood. Various biomacromolecules have been identified to exhibit LLPS properties in different bacterial species. LLPS which is introduced into synthetic biology applies to bacteria has important implications, and three recent research reports have shed light on its potential applications in this field. Overall, this review investigates the molecular mechanisms of LLPS occurrence and its significance in bacteria while also considering the future prospects of implementing LLPS in synthetic biology.
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Affiliation(s)
- Dong Guo
- School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Yan Xiong
- School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Beibei Fu
- School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Zhou Sha
- School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Bohao Li
- School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Haibo Wu
- School of Life Sciences, Chongqing University, Chongqing 401331, China.
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9
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Kuzminov A. Bacterial nucleoid is a riddle wrapped in a mystery inside an enigma. J Bacteriol 2024; 206:e0021123. [PMID: 38358278 PMCID: PMC10994824 DOI: 10.1128/jb.00211-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024] Open
Abstract
Bacterial chromosome, the nucleoid, is traditionally modeled as a rosette of DNA mega-loops, organized around proteinaceous central scaffold by nucleoid-associated proteins (NAPs), and mixed with the cytoplasm by transcription and translation. Electron microscopy of fixed cells confirms dispersal of the cloud-like nucleoid within the ribosome-filled cytoplasm. Here, I discuss evidence that the nucleoid in live cells forms DNA phase separate from riboprotein phase, the "riboid." I argue that the nucleoid-riboid interphase, where DNA interacts with NAPs, transcribing RNA polymerases, nascent transcripts, and ssRNA chaperones, forms the transcription zone. An active part of phase separation, transcription zone enforces segregation of the centrally positioned information phase (the nucleoid) from the surrounding action phase (the riboid), where translation happens, protein accumulates, and metabolism occurs. I speculate that HU NAP mostly tiles up the nucleoid periphery-facilitating DNA mobility but also supporting transcription in the interphase. Besides extruding plectonemically supercoiled DNA mega-loops, condensins could compact them into solenoids of uniform rings, while HU could support rigidity and rotation of these DNA rings. The two-phase cytoplasm arrangement allows the bacterial cell to organize the central dogma activities, where (from the cell center to its periphery) DNA replicates and segregates, DNA is transcribed, nascent mRNA is handed over to ribosomes, mRNA is translated into proteins, and finally, the used mRNA is recycled into nucleotides at the inner membrane. The resulting information-action conveyor, with one activity naturally leading to the next one, explains the efficiency of prokaryotic cell design-even though its main intracellular transportation mode is free diffusion.
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Affiliation(s)
- Andrei Kuzminov
- Department of Microbiology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
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10
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Miyakoshi M. Multilayered regulation of amino acid metabolism in Escherichia coli. Curr Opin Microbiol 2024; 77:102406. [PMID: 38061078 DOI: 10.1016/j.mib.2023.102406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/08/2023] [Accepted: 11/09/2023] [Indexed: 02/12/2024]
Abstract
Amino acid metabolism in Escherichia coli has long been studied and has established the basis for regulatory mechanisms at the transcriptional, posttranscriptional, and posttranslational levels. In addition to the classical signal transduction cascade involving posttranslational modifications (PTMs), novel PTMs in the two primary nitrogen assimilation pathways have recently been uncovered. The regulon of the master transcriptional regulator NtrC is further expanded by a small RNA derived from the 3´UTR of glutamine synthetase mRNA, which coordinates central carbon and nitrogen metabolism. Furthermore, recent advances in sequencing technologies have revealed the global regulatory networks of transcriptional and posttranscriptional regulators, Lrp and GcvB. This review provides an update of the multilayered and interconnected regulatory networks governing amino acid metabolism in E. coli.
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Affiliation(s)
- Masatoshi Miyakoshi
- Department of Infection Biology, Institute of Medicine, University of Tsukuba, 305-8575 Ibaraki, Japan.
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11
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Kannaiah S, Goldberger O, Alam N, Barnabas G, Pozniak Y, Nussbaum-Shochat A, Schueler-Furman O, Geiger T, Amster-Choder O. MinD-RNase E interplay controls localization of polar mRNAs in E. coli. EMBO J 2024; 43:637-662. [PMID: 38243117 PMCID: PMC10897333 DOI: 10.1038/s44318-023-00026-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 12/11/2023] [Accepted: 12/18/2023] [Indexed: 01/21/2024] Open
Abstract
The E. coli transcriptome at the cell's poles (polar transcriptome) is unique compared to the membrane and cytosol. Several factors have been suggested to mediate mRNA localization to the membrane, but the mechanism underlying polar localization of mRNAs remains unknown. Here, we combined a candidate system approach with proteomics to identify factors that mediate mRNAs localization to the cell poles. We identified the pole-to-pole oscillating protein MinD as an essential factor regulating polar mRNA localization, although it is not able to bind RNA directly. We demonstrate that RNase E, previously shown to interact with MinD, is required for proper localization of polar mRNAs. Using in silico modeling followed by experimental validation, the membrane-binding site in RNase E was found to mediate binding to MinD. Intriguingly, not only does MinD affect RNase E interaction with the membrane, but it also affects its mode of action and dynamics. Polar accumulation of RNase E in ΔminCDE cells resulted in destabilization and depletion of mRNAs from poles. Finally, we show that mislocalization of polar mRNAs may prevent polar localization of their protein products. Taken together, our findings show that the interplay between MinD and RNase E determines the composition of the polar transcriptome, thus assigning previously unknown roles for both proteins.
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Affiliation(s)
- Shanmugapriya Kannaiah
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University Faculty of Medicine, P.O.Box 12272, 91120, Jerusalem, Israel.
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, MO, 63110, USA.
| | - Omer Goldberger
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University Faculty of Medicine, P.O.Box 12272, 91120, Jerusalem, Israel
| | - Nawsad Alam
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University Faculty of Medicine, P.O.Box 12272, 91120, Jerusalem, Israel
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
| | - Georgina Barnabas
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, 6997801, Tel-Aviv, Israel
- Department of Pathology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Yair Pozniak
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, 6997801, Tel-Aviv, Israel
| | - Anat Nussbaum-Shochat
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University Faculty of Medicine, P.O.Box 12272, 91120, Jerusalem, Israel
| | - Ora Schueler-Furman
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University Faculty of Medicine, P.O.Box 12272, 91120, Jerusalem, Israel
| | - Tamar Geiger
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, 6997801, Tel-Aviv, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, 76100001, Rehovot, Israel
| | - Orna Amster-Choder
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University Faculty of Medicine, P.O.Box 12272, 91120, Jerusalem, Israel.
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12
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Turbant F, Machiels Q, Waeytens J, Wien F, Arluison V. The Amyloid Assembly of the Bacterial Hfq Is Lipid-Driven and Lipid-Specific. Int J Mol Sci 2024; 25:1434. [PMID: 38338713 PMCID: PMC10855545 DOI: 10.3390/ijms25031434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 01/20/2024] [Accepted: 01/22/2024] [Indexed: 02/12/2024] Open
Abstract
Under specific conditions, some proteins can self-assemble into fibrillar structures called amyloids. Initially, these proteins were associated with neurodegenerative diseases in eucaryotes. Nevertheless, they have now been identified in the three domains of life. In bacteria, they are involved in diverse biological processes and are usually useful for the cell. For this reason, they are classified as "functional amyloids". In this work, we focus our analysis on a bacterial functional amyloid called Hfq. Hfq is a pleiotropic regulator that mediates several aspects of genetic expression, mainly via the use of small noncoding RNAs. Our previous work showed that Hfq amyloid-fibrils interact with membranes. This interaction influences Hfq amyloid structure formation and stability, but the specifics of the lipid on the dynamics of this process is unknown. Here, we show, using spectroscopic methods, how lipids specifically drive and modulate Hfq amyloid assembly or, conversely, its disassembly. The reported effects are discussed in light of the consequences for bacterial cell life.
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Affiliation(s)
- Florian Turbant
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, CEA Saclay, 91191 Gif-sur-Yvette, France;
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint Aubin BP48, 91192 Gif-sur-Yvette, France;
- Department of Molecular Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland
| | - Quentin Machiels
- Structure et Fonction des Membranes Biologiques, Université Libre de Bruxelles, 1050 Bruxelles, Belgium; (Q.M.); (J.W.)
| | - Jehan Waeytens
- Structure et Fonction des Membranes Biologiques, Université Libre de Bruxelles, 1050 Bruxelles, Belgium; (Q.M.); (J.W.)
- Unit of Pharmacognosy, Bioanalysis and Drug Discovery, Université Libre de Bruxelles, 1050 Bruxelles, Belgium
| | - Frank Wien
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint Aubin BP48, 91192 Gif-sur-Yvette, France;
| | - Véronique Arluison
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, CEA Saclay, 91191 Gif-sur-Yvette, France;
- SDV Department, Université Paris Cité, 75006 Paris, France
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13
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Nandana V, Al-Husini N, Vaishnav A, Dilrangi KH, Schrader JM. Caulobacter crescentus RNase E condensation contributes to autoregulation and fitness. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.15.571756. [PMID: 38168245 PMCID: PMC10760160 DOI: 10.1101/2023.12.15.571756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
RNase E is the most common RNA decay nuclease in bacteria, setting the global mRNA decay rate and scaffolding formation of the RNA degradosome complex and BR-bodies. To properly set the global mRNA decay rate, RNase E from Escherichia coli and neighboring γ-proteobacteria were found to autoregulate RNase E levels via the decay of its mRNA's 5' UTR. While the 5' UTR is absent from other groups of bacteria in the Rfam database, we identified that the α-proteobacterium Caulobacter crescentus RNase E contains a similar 5' UTR structure that promotes RNase E autoregulation. In both bacteria, the C-terminal IDR of RNase E is required for proper autoregulation to occur, and this IDR is also necessary and sufficient for RNase E to phase-separate, generating BR-bodies. Using in vitro purified RNase E, we find that the IDR's ability to promote phase-separation correlates with enhanced 5' UTR cleavage, suggesting that phase-separation of RNase E with the 5' UTR enhances autoregulation. Finally, using growth competition experiments we find that a strain capable of autoregulation rapidly outcompetes a strain with a 5' UTR mutation that cannot autoregulate, suggesting autoregulation promotes optimal cellular fitness.
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Affiliation(s)
- Vidhyadhar Nandana
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202
| | - Nadra Al-Husini
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202
| | | | | | - Jared M. Schrader
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202
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14
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Szoke T, Goldberger O, Albocher-Kedem N, Barsheshet M, Dezorella N, Nussbaum-Shochat A, Wiener R, Schuldiner M, Amster-Choder O. Regulation of major bacterial survival strategies by transcripts sequestration in a membraneless organelle. Cell Rep 2023; 42:113393. [PMID: 37934665 DOI: 10.1016/j.celrep.2023.113393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 08/10/2023] [Accepted: 10/20/2023] [Indexed: 11/09/2023] Open
Abstract
TmaR, the only known pole-localizer protein in Escherichia coli, was shown to cluster at the cell poles and control localization and activity of the major sugar regulator in a tyrosine phosphorylation-dependent manner. Here, we show that TmaR assembles by phase separation (PS) via heterotypic interactions with RNA in vivo and in vitro. An unbiased automated mutant screen combined with directed mutagenesis and genetic manipulations uncovered the importance of a predicted nucleic-acid-binding domain, a disordered region, and charged patches, one containing the phosphorylated tyrosine, for TmaR condensation. We demonstrate that, by protecting flagella-related transcripts, TmaR controls flagella production and, thus, cell motility and biofilm formation. These results connect PS in bacteria to survival and provide an explanation for the linkage between metabolism and motility. Intriguingly, a point mutation or increase in its cellular concentration induces irreversible liquid-to-solid transition of TmaR, similar to human disease-causing proteins, which affects cell morphology and division.
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Affiliation(s)
- Tamar Szoke
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University Faculty of Medicine, Jerusalem 91120, Israel
| | - Omer Goldberger
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University Faculty of Medicine, Jerusalem 91120, Israel
| | - Nitsan Albocher-Kedem
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University Faculty of Medicine, Jerusalem 91120, Israel
| | - Meshi Barsheshet
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University Faculty of Medicine, Jerusalem 91120, Israel
| | - Nili Dezorella
- Electron Microscopy Unit, The Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Anat Nussbaum-Shochat
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University Faculty of Medicine, Jerusalem 91120, Israel
| | - Reuven Wiener
- Department of Biochemistry and Molecular Biology, IMRIC, The Hebrew University Faculty of Medicine, Jerusalem 91120, Israel
| | - Maya Schuldiner
- Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Orna Amster-Choder
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University Faculty of Medicine, Jerusalem 91120, Israel.
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15
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Nandana V, Rathnayaka-Mudiyanselage IW, Muthunayake NS, Hatami A, Mousseau CB, Ortiz-Rodríguez LA, Vaishnav J, Collins M, Gega A, Mallikaarachchi KS, Yassine H, Ghosh A, Biteen JS, Zhu Y, Champion MM, Childers WS, Schrader JM. The BR-body proteome contains a complex network of protein-protein and protein-RNA interactions. Cell Rep 2023; 42:113229. [PMID: 37815915 PMCID: PMC10842194 DOI: 10.1016/j.celrep.2023.113229] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 07/16/2023] [Accepted: 09/22/2023] [Indexed: 10/12/2023] Open
Abstract
Bacterial ribonucleoprotein bodies (BR-bodies) are non-membrane-bound structures that facilitate mRNA decay by concentrating mRNA substrates with RNase E and the associated RNA degradosome machinery. However, the full complement of proteins enriched in BR-bodies has not been defined. Here, we define the protein components of BR-bodies through enrichment of the bodies followed by mass spectrometry-based proteomic analysis. We find 111 BR-body-enriched proteins showing that BR-bodies are more complex than previously assumed. We identify five BR-body-enriched proteins that undergo RNA-dependent phase separation in vitro with a complex network of condensate mixing. We observe that some RNP condensates co-assemble with preferred directionality, suggesting that RNA may be trafficked through RNP condensates in an ordered manner to facilitate mRNA processing/decay, and that some BR-body-associated proteins have the capacity to dissolve the condensate. Altogether, these results suggest that a complex network of protein-protein and protein-RNA interactions controls BR-body phase separation and RNA processing.
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Affiliation(s)
- Vidhyadhar Nandana
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Imalka W Rathnayaka-Mudiyanselage
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA; Department of Chemistry, Wayne State University, Detroit, MI 48202, USA
| | | | - Ali Hatami
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI 48202, USA
| | - C Bruce Mousseau
- Department of Chemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | | | - Jamuna Vaishnav
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI 48202, USA
| | - Michael Collins
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Alisa Gega
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | | | - Hadi Yassine
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Aishwarya Ghosh
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Julie S Biteen
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Yingxi Zhu
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI 48202, USA
| | - Matthew M Champion
- Department of Chemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - W Seth Childers
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Jared M Schrader
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA.
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16
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Berbon M, Martinez D, Morvan E, Grélard A, Kauffmann B, Waeytens J, Wien F, Arluison V, Habenstein B. Hfq C-terminal region forms a β-rich amyloid-like motif without perturbing the N-terminal Sm-like structure. Commun Biol 2023; 6:1075. [PMID: 37865695 PMCID: PMC10590398 DOI: 10.1038/s42003-023-05462-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 10/13/2023] [Indexed: 10/23/2023] Open
Abstract
Hfq is a pleitropic actor that serves as stress response and virulence factor in the bacterial cell. To execute its multiple functions, Hfq assembles into symmetric torus-shaped hexamers. Extending outward from the hexameric core, Hfq presents a C-terminal region, described as intrinsically disordered in solution. Many aspects of the role and the structure of this region remain unclear. For instance, in its truncated form it can promote amyloid-like filament assembly. Here, we show that a minimal 11-residue motif at the C-terminal end of Hfq assembles into filaments with amyloid characteristics. Our data suggest that the full-length Hfq in its filamentous state contains a similar molecular fingerprint than that of the short β-strand peptide, and that the Sm-core structure is not affected by filament formation. Hfq proteins might thus co-exist in two forms in vivo, either as isolated, soluble hexamers or as self-assembled hexamers through amyloid-reminiscent interactions, modulating Hfq cellular functions.
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Affiliation(s)
- Mélanie Berbon
- Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, IECB, Pessac, France
| | - Denis Martinez
- Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, IECB, Pessac, France
| | - Estelle Morvan
- Univ. Bordeaux, CNRS, INSERM, IECB, UAR 3033, Pessac, France
| | - Axelle Grélard
- Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, IECB, Pessac, France
| | - Brice Kauffmann
- Univ. Bordeaux, CNRS, INSERM, IECB, UAR 3033, Pessac, France
| | - Jehan Waeytens
- Structure et Fonction des Membranes Biologiques, Université libre de Bruxelles, Bruxelles, Belgique
| | - Frank Wien
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin BP48, 91192, Gif-sur-Yvette, France
| | - Véronique Arluison
- Laboratoire Léon Brillouin LLB, UMR12 CEA CNRS, CEA Saclay, 91191, Gif-sur-Yvette, France.
- Université de Paris Cité, UFR SDV, 75013, Paris, France.
| | - Birgit Habenstein
- Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, IECB, Pessac, France.
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17
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Borodavka A, Acker J. Seeing Biomolecular Condensates Through the Lens of Viruses. Annu Rev Virol 2023; 10:163-182. [PMID: 37040799 DOI: 10.1146/annurev-virology-111821-103226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
Phase separation of viral biopolymers is a key factor in the formation of cytoplasmic viral inclusions, known as sites of virus replication and assembly. This review describes the mechanisms and factors that affect phase separation in viral replication and identifies potential areas for future research. Drawing inspiration from studies on cellular RNA-rich condensates, we compare the hierarchical coassembly of ribosomal RNAs and proteins in the nucleolus to the coordinated coassembly of viral RNAs and proteins taking place within viral factories in viruses containing segmented RNA genomes. We highlight the common characteristics of biomolecular condensates in viral replication and how this new understanding is reshaping our views of virus assembly mechanisms. Such studies have the potential to uncover unexplored antiviral strategies targeting these phase-separated states.
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Affiliation(s)
- Alexander Borodavka
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom;
| | - Julia Acker
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom;
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18
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Nandana V, Rathnayaka-Mudiyanselage IW, Muthunayak NS, Hatami A, Mousseau CB, Ortiz-Rodríguez LA, Vaishnav J, Collins M, Gega A, Mallikaarachchi KS, Yassine H, Ghosh A, Biteen JS, Zhu Y, Champion MM, Childers WS, Schrader JM. The BR-body proteome contains a complex network of protein-protein and protein-RNA interactions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.18.524314. [PMID: 36712072 PMCID: PMC9882336 DOI: 10.1101/2023.01.18.524314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Bacterial RNP bodies (BR-bodies) are non-membrane-bound structures that facilitate mRNA decay by concentrating mRNA substrates with RNase E and the associated RNA degradosome machinery. However, the full complement of proteins enriched in BR-bodies has not been defined. Here we define the protein components of BR-bodies through enrichment of the bodies followed by mass spectrometry-based proteomic analysis. We found 111 BR-body enriched proteins, including several RNA binding proteins, many of which are also recruited directly to in vitro reconstituted RNase E droplets, showing BR-bodies are more complex than previously assumed. While most BR-body enriched proteins that were tested cannot phase separate, we identified five that undergo RNA-dependent phase separation in vitro, showing other RNP condensates interface with BR-bodies. RNA degradosome protein clients are recruited more strongly to RNase E droplets than droplets of other RNP condensates, implying that client specificity is largely achieved through direct protein-protein interactions. We observe that some RNP condensates assemble with preferred directionally, suggesting that RNA may be trafficked through RNP condensates in an ordered manner to facilitate mRNA processing/decay, and that some BR-body associated proteins have the capacity to dissolve the condensate. Finally, we find that RNA dramatically stimulates the rate of RNase E phase separation in vitro, explaining the dissolution of BR-bodies after cellular mRNA depletion observed previously. Altogether, these results suggest that a complex network of protein-protein and protein-RNA interactions controls BR-body phase separation and RNA processing.
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Affiliation(s)
- V Nandana
- Wayne State University, Department of Biological Sciences, Detroit, MI
| | - I W Rathnayaka-Mudiyanselage
- Wayne State University, Department of Biological Sciences, Detroit, MI
- Wayne State University, Department of Chemistry, Detroit, MI
| | - N S Muthunayak
- Wayne State University, Department of Biological Sciences, Detroit, MI
| | - A Hatami
- Wayne State University, Department of Chemical Engineering and Materials Science, Detroit, MI
| | - C B Mousseau
- University of Notre Dame, Department of Chemistry, Notre Dame, IN
| | | | - J Vaishnav
- Wayne State University, Department of Chemical Engineering and Materials Science, Detroit, MI
| | - M Collins
- University of Pittsburgh, Department of Chemistry, Pittsburgh, PA
| | - A Gega
- Wayne State University, Department of Biological Sciences, Detroit, MI
| | | | - H Yassine
- Wayne State University, Department of Biological Sciences, Detroit, MI
| | - A Ghosh
- Wayne State University, Department of Biological Sciences, Detroit, MI
| | - J S Biteen
- University of Michigan, Department of Chemistry, Ann Arbor, MI
| | - Y Zhu
- Wayne State University, Department of Chemical Engineering and Materials Science, Detroit, MI
| | - M M Champion
- University of Notre Dame, Department of Chemistry, Notre Dame, IN
| | - W S Childers
- University of Pittsburgh, Department of Chemistry, Pittsburgh, PA
| | - J M Schrader
- Wayne State University, Department of Biological Sciences, Detroit, MI
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