1
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Sommerfield AG, Wang M, Mamana J, Darwin AJ. In vivo and in vitro analysis of the role of the Prc protease in inducing mucoidy in Pseudomonas aeruginosa. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.28.596254. [PMID: 38854061 PMCID: PMC11160602 DOI: 10.1101/2024.05.28.596254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
In Pseudomonas aeruginosa, alginate biosynthesis gene expression is inhibited by the transmembrane anti-sigma factor MucA, which sequesters the AlgU sigma factor. Cell envelope stress initiates cleavage of the MucA periplasmic domain by site-1 protease AlgW, followed by further MucA degradation to release AlgU. However, after colonizing the lungs of people with cystic fibrosis, P. aeruginosa converts to a mucoid form that produces alginate constitutively. Mucoid isolates often have mucA mutations, with the most common being mucA22 , which truncates the periplasmic domain. MucA22 is degraded constitutively, and genetic studies suggested that the Prc protease is responsible. Some studies also suggested that Prc contributes to induction in strains with wild type MucA, whereas others suggested the opposite. However, missing from all previous studies is a demonstration that Prc cleaves any protein directly, which leaves open the possibility that the effect of a prc null mutation is indirect. To address the ambiguities and shortfalls, we reevaluated the roles of AlgW and Prc as MucA and MucA22 site-1 proteases. In vivo analyses using three different assays, and two different inducing conditions, all suggested that AlgW is the only site-1 protease for wild type MucA in any condition. In contrast, genetics suggested that AlgW or Prc act as MucA22 site-1 proteases in inducing conditions, whereas Prc is the only MucA22 site-1 protease in non-inducing conditions. For the first time, we also show that Prc is unable to degrade the periplasmic domain of wild type MucA, but does degrade the mutated periplasmic domain of MucA22 directly. IMPORTANCE After colonizing the lungs of individuals with cystic fibrosis, P. aeruginosa undergoes mutagenic conversion to a mucoid form, worsening the prognosis. Most mucoid isolates have a truncated negative regulatory protein MucA, which leads to constitutive production of the extracellular polysaccharide alginate. The protease Prc has been implicated, but not shown, to degrade the most common MucA variant, MucA22, to trigger alginate production. This work provides the first demonstration that the molecular mechanism of Prc involvement is direct degradation of the MucA22 periplasmic domain, and perhaps other truncated MucA variants as well. MucA truncation and degradation by Prc might be the predominant mechanism of mucoid conversion in cystic fibrosis infections, suggesting that Prc activity could be a useful therapeutic target.
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2
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Pollack D, Nozoe T, Kussell E. Proteolytic stability and aggregation in a key metabolic enzyme of bacteria. Proc Natl Acad Sci U S A 2024; 121:e2301458121. [PMID: 38683989 PMCID: PMC11087809 DOI: 10.1073/pnas.2301458121] [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: 01/31/2023] [Accepted: 03/07/2024] [Indexed: 05/02/2024] Open
Abstract
Proteins that are kinetically stable are thought to be less prone to both aggregation and proteolysis. We demonstrate that the classical lac system of Escherichia coli can be leveraged as a model system to study this relation. β-galactosidase (LacZ) plays a critical role in lactose metabolism and is an extremely stable protein that can persist in growing cells for multiple generations after expression has stopped. By attaching degradation tags to the LacZ protein, we find that LacZ can be transiently degraded during lac operon expression but once expression has stopped functional LacZ is protected from degradation. We reversibly destabilize its tetrameric assembly using α-complementation, and show that unassembled LacZ monomers and dimers can either be degraded or lead to formation of aggregates within cells, while the tetrameric state protects against proteolysis and aggregation. We show that the presence of aggregates is associated with cell death, and that these proteotoxic stress phenotypes can be alleviated by attaching an ssrA tag to LacZ monomers which leads to their degradation. We unify our findings using a biophysical model that enables the interplay of protein assembly, degradation, and aggregation to be studied quantitatively in vivo. This work may yield approaches to reversing and preventing protein-misfolding disease states, while elucidating the functions of proteolytic stability in constant and fluctuating environments.
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Affiliation(s)
- Dan Pollack
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY10003
| | - Takashi Nozoe
- Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo153-8902, Japan
- Research Center for Complex Systems Biology, The University of Tokyo, Tokyo153-8902, Japan
- Universal Biology Institute, The University of Tokyo, Tokyo113-0033, Japan
| | - Edo Kussell
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY10003
- Department of Physics, New York University, New York, NY10003
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3
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Delgadillo-Guevara M, Halte M, Erhardt M, Popp PF. Fluorescent tools for the standardized work in Gram-negative bacteria. J Biol Eng 2024; 18:25. [PMID: 38589953 PMCID: PMC11003136 DOI: 10.1186/s13036-024-00420-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Accepted: 03/18/2024] [Indexed: 04/10/2024] Open
Abstract
Standardized and thoroughly characterized genetic tools are a prerequisite for studying cellular processes to ensure the reusability and consistency of experimental results. The discovery of fluorescent proteins (FPs) represents a milestone in the development of genetic reporters for monitoring transcription or protein localization in vivo. FPs have revolutionized our understanding of cellular dynamics by enabling the real-time visualization and tracking of biological processes. Despite these advancements, challenges remain in the appropriate use of FPs, specifically regarding their proper application, protein turnover dynamics, and the undesired disruption of cellular functions. Here, we systematically compared a comprehensive set of 15 FPs and assessed their performance in vivo by focusing on key parameters, such as signal over background ratios and protein stability rates, using the Gram-negative model organism Salmonella enterica as a representative host. We evaluated four protein degradation tags in both plasmid- and genome-based systems and our findings highlight the necessity of introducing degradation tags to analyze time-sensitive cellular processes. We demonstrate that the gain of dynamics mediated by the addition of degradation tags impacts the cell-to-cell heterogeneity of plasmid-based but not genome-based reporters. Finally, we probe the applicability of FPs for protein localization studies in living cells using standard and super-resolution fluorescence microscopy. In summary, our study underscores the importance of careful FP selection and paves the way for the development of improved genetic reporters to enhance the reproducibility and reliability of fluorescence-based research in Gram-negative bacteria and beyond.
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Affiliation(s)
- Mario Delgadillo-Guevara
- Institute of Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, 10115, Germany
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC, Australia
| | - Manuel Halte
- Institute of Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, 10115, Germany
| | - Marc Erhardt
- Institute of Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, 10115, Germany
- Max Planck Unit for the Science of Pathogens, Berlin, 10117, Germany
| | - Philipp F Popp
- Institute of Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, 10115, Germany.
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4
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Chaisupa P, Wright RC. State-of-the-art in engineering small molecule biosensors and their applications in metabolic engineering. SLAS Technol 2024; 29:100113. [PMID: 37918525 DOI: 10.1016/j.slast.2023.10.005] [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: 07/07/2023] [Revised: 10/18/2023] [Accepted: 10/25/2023] [Indexed: 11/04/2023]
Abstract
Genetically encoded biosensors are crucial for enhancing our understanding of how molecules regulate biological systems. Small molecule biosensors, in particular, help us understand the interaction between chemicals and biological processes. They also accelerate metabolic engineering by increasing screening throughput and eliminating the need for sample preparation through traditional chemical analysis. Additionally, they offer significantly higher spatial and temporal resolution in cellular analyte measurements. In this review, we discuss recent progress in in vivo biosensors and control systems-biosensor-based controllers-for metabolic engineering. We also specifically explore protein-based biosensors that utilize less commonly exploited signaling mechanisms, such as protein stability and induced degradation, compared to more prevalent transcription factor and allosteric regulation mechanism. We propose that these lesser-used mechanisms will be significant for engineering eukaryotic systems and slower-growing prokaryotic systems where protein turnover may facilitate more rapid and reliable measurement and regulation of the current cellular state. Lastly, we emphasize the utilization of cutting-edge and state-of-the-art techniques in the development of protein-based biosensors, achieved through rational design, directed evolution, and collaborative approaches.
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Affiliation(s)
- Patarasuda Chaisupa
- Department of Biological Systems Engineering, Virginia Tech, Blacksburg, VA 24061, United States
| | - R Clay Wright
- Department of Biological Systems Engineering, Virginia Tech, Blacksburg, VA 24061, United States; Translational Plant Sciences Center (TPSC), Virginia Tech, Blacksburg, VA 24061, United States.
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5
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Ishikawa F, Homma M, Tanabe G, Uchihashi T. [Protein degradation in bacteria: focus on the ClpP protease]. Nihon Saikingaku Zasshi 2024; 79:1-13. [PMID: 38382970 DOI: 10.3412/jsb.79.1] [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: 02/23/2024]
Abstract
Proteins in the cells are born (synthesized), work, and die (decomposed). In the life of a protein, its birth is obviously important, but how it dies is equally important in living organisms. Proteases secreted into the outside of cells are used to decompose the external proteins and the degradation products are taken as the nutrients. On the other hand, there are also proteases that decompose unnecessary or harmful proteins which are generated in the cells. In eukaryotes, a large enzyme complex called the proteasome is primarily responsible for degradation of such proteins. Bacteria, which are prokaryotes, have a similar system as the proteasome. We would like to explain the bacterial degradation system of proteins or the death of proteins, which is performed by ATP-dependent protease Clp, with a particular focus on the ClpXP complex, and with an aspect as a target for antibiotics against bacteria.
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Affiliation(s)
| | - Michio Homma
- Division of Physics, Graduate School of Science, Nagoya University
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6
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Alwahsh M, Farhat J, Talhouni S, Hamadneh L, Hergenröder R. Bortezomib advanced mechanisms of action in multiple myeloma, solid and liquid tumors along with its novel therapeutic applications. EXCLI JOURNAL 2023; 22:146-168. [PMID: 36998701 PMCID: PMC10043448 DOI: 10.17179/excli2022-5653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 01/12/2023] [Indexed: 04/01/2023]
Abstract
Bortezomib (BTZ) is a first-in-class reversible and selective proteasome inhibitor. It inhibits the ubiquitin proteasome pathway that leads to the degradation of many intracellular proteins. Initially, BTZ was FDA approved for the treatment of refractory or relapsed multiple myeloma (MM) in 2003. Later, its usage was approved for patients with previously untreated MM. In 2006, BTZ was approved for the treatment of relapsed or refractory Mantle Cell Lymphoma (MCL) and, in 2014, for previously untreated MCL. BTZ has been extensively studied either alone or in combination with other drugs for the treatment of different liquid tumors especially in MM. However, limited data evaluated the efficacy and safety of using BTZ in patients with solid tumors. In this review, we will discuss the advanced and novel mechanisms of action of BTZ documented in MM, solid tumors and liquid tumors. Moreover, we will shed the light on the newly discovered pharmacological effects of BTZ in other prevalent diseases.
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Affiliation(s)
- Mohammad Alwahsh
- Department of Pharmacy, Faculty of Pharmacy, Al-Zaytoonah University of Jordan, P.O. Box 130, Amman, 11733, Jordan
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., 44139 Dortmund, Germany
- Institute of Pathology and Medical Research Center (ZMF), University Medical Center Mannheim, Heidelberg University, 68167 Mannheim, Germany
- *To whom correspondence should be addressed: Mohammad Alwahsh, Department of Pharmacy, Faculty of Pharmacy, Al-Zaytoonah University of Jordan, P.O. Box 130, Amman, 11733, Jordan, E-mail:
| | - Joviana Farhat
- Department of Epidemiology and Population Health, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi, PO Box 127788, United Arab Emirates
| | - Shahd Talhouni
- Department of Pharmacy, Faculty of Pharmacy, Al-Zaytoonah University of Jordan, P.O. Box 130, Amman, 11733, Jordan
| | - Lama Hamadneh
- Department of Pharmacy, Faculty of Pharmacy, Al-Zaytoonah University of Jordan, P.O. Box 130, Amman, 11733, Jordan
| | - Roland Hergenröder
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., 44139 Dortmund, Germany
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7
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Wu Y, Tang M, Wang Z, Yang Y, Li Z, Liang S, Yin P, Qi H. Efficient In Vitro Full-Sense-Codons Protein Synthesis. Adv Biol (Weinh) 2022; 6:e2200023. [PMID: 35676219 DOI: 10.1002/adbi.202200023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 04/14/2022] [Indexed: 01/28/2023]
Abstract
Termination of translation is essential but hinders applications of genetic code engineering, e.g., unnatural amino acids incorporation and codon randomization mediated saturation mutagenesis. Here, for the first time, it is demonstrated that E. coli Pth and ArfB together play an efficient translation termination without codon preference in the absence of class-I release factors. By degradation of the targeted protein, both essential and alternative termination types of machinery are completely removed to disable codon-dependent termination in cell extract. Moreover, a total of 153 engineered tRNAs are screened for efficient all stop-codons decoding to construct a codon-dependent termination defect in vitro protein synthesis with all 64 sense-codons, iPSSC. Finally, this full sense genetic code achieves significant improvement in the incorporation of distinct unnatural amino acids at up to 12 positions and synthesis of protein encoding consecutive NNN codons. By decoding all information in nucleotides to amino acids, iPSSC may hold great potential in building artificial protein synthesis beyond the cell.
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Affiliation(s)
- Yang Wu
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin, China.,College of Life Sciences, Hebei Agricultural University, Baoding, Hebei, China
| | - Mengtong Tang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin, China
| | - Zhaoguan Wang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin, China
| | - Youhui Yang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin, China
| | - Zhong Li
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin, China
| | - Shurui Liang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin, China
| | - Peng Yin
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin, China
| | - Hao Qi
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin, China.,Zhejiang Institute of Tianjin University, Shaoxing, Zhejiang, China
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8
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Jadhav P, Chen Y, Butzin N, Buceta J, Urchueguía A. Bacterial degrons in synthetic circuits. Open Biol 2022; 12:220180. [PMID: 35975648 PMCID: PMC9382460 DOI: 10.1098/rsob.220180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bacterial proteases are a promising post-translational regulation strategy in synthetic circuits because they recognize specific amino acid degradation tags (degrons) that can be fine-tuned to modulate the degradation levels of tagged proteins. For this reason, recent efforts have been made in the search for new degrons. Here we review the up-to-date applications of degradation tags for circuit engineering in bacteria. In particular, we pay special attention to the effects of degradation bottlenecks in synthetic oscillators and introduce mathematical approaches to study queueing that enable the quantitative modelling of proteolytic queues.
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Affiliation(s)
- Prajakta Jadhav
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, USA
| | - Yanyan Chen
- Program for Computational and Systems Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Nicholas Butzin
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, USA
| | - Javier Buceta
- Institute for Integrative Systems Biology (I2SysBio, CSIC-UV), Paterna, Valencia 46980, Spain
| | - Arantxa Urchueguía
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, USA.,Institute for Integrative Systems Biology (I2SysBio, CSIC-UV), Paterna, Valencia 46980, Spain
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9
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Bacterial Carboxyl-Terminal Processing Proteases Play Critical Roles in the Cell Envelope and Beyond. J Bacteriol 2022; 204:e0062821. [PMID: 35293777 PMCID: PMC9017358 DOI: 10.1128/jb.00628-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Proteolysis is essential throughout life, and as more proteases are characterized, our understanding of the roles they play continues to expand. Among other things, proteases are critical for protein turnover and quality control, the activation or inactivation of some enzymes, and they are integral components of signal transduction pathways. This review focuses on a family of proteases in bacteria known as the carboxyl-terminal processing proteases, or CTPs. Members of this family occur in all domains of life. In bacteria, CTPs have emerged as important enzymes that have been implicated in critical processes including regulation, stress response, peptidoglycan remodeling, and virulence. Here, we provide an overview of the roles that CTPs play in diverse bacterial species, and some of the underlying mechanisms. We also describe the structures of some bacterial CTPs, and their adaptor proteins, which have revealed striking differences in arrangements and mechanisms of action. Finally, we discuss what little is known about the distinguishing features of CTP substrates and cleavage sites, and speculate about how CTP activities might be regulated in the bacterial cell. Compared with many other proteases, the study of bacterial CTPs is still in its infancy, but it has now become clear that they affect fundamental processes in many different species. This is a protease family with broad significance, and one that holds the promise of more high impact discoveries to come.
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10
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Zübert C, Ilic AM, Duduk B, Kube M. The Genome Reduction Excludes the Ribosomal Rescue System in Acholeplasmataceae. Microb Physiol 2022; 32:45-56. [PMID: 35100600 DOI: 10.1159/000520450] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 10/24/2021] [Indexed: 11/19/2022]
Abstract
The trans-translation process is a ribosomal rescue system for stalled ribosomes processing truncated mRNA. The genes ssrA and smpB fulfil the key functions in most bacteria, but some species have either lost these genes or the function of the ribosomal rescue system is taken over by other genes. To date, the ribosomal rescue system has not been analysed in detail for the Acholeplasmataceae. This family, in the Mollicutes class, comprises the genus Acholeplasma and the provisional taxon "Candidatus Phytoplasma". Despite their monophyletic origin, the two clades can be separated by traits such as not representing primary pathogens for acholeplasmas versus being phytopathogenic for the majority of phytoplasmas. Both taxa share reduced genomes, but only phytoplasma genomes are characterised by a remarkable level of instability and reduction. Despite the general relevance of the ribosomal rescue system, information is lacking on coding, the genomic context and pseudogenisation of smpB and ssrA and their possible application as a phylogenetic marker. Herein, we provide a comprehensive analysis of the ribosomal rescue system in members of Acholeplasmataceae. The examined Acholeplasmataceae genomes encode a ribosomal rescue system, which depends on tmRNA encoded by ssrA acting in combination with its binding protein SmpB. Conserved gene synteny is evident for smpB, while ssrA shows a less conserved genomic context. Analysis of the tmRNA sequences highlights the variability of proteolysis tag sequences and short conserved sites at the 5'- and 3'-ends. Analyses of smpB provided no hints regarding the coding of pseudogenes, but they did suggest its application as a phylogenetic marker of Acholeplasmataceae - in accordance with 16S rDNA topology. Sequence variability of smpB provides sufficient information for species assignment and phylogenetic analysis.
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Affiliation(s)
- Christina Zübert
- Integrative Infection Biology Crops-Livestock, University of Hohenheim, Stuttgart, Germany
| | - Anna-Marie Ilic
- Integrative Infection Biology Crops-Livestock, University of Hohenheim, Stuttgart, Germany
| | - Bojan Duduk
- Institute of Pesticides and Environmental Protection, Belgrade, Serbia
| | - Michael Kube
- Integrative Infection Biology Crops-Livestock, University of Hohenheim, Stuttgart, Germany
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11
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The Molecular Toolset and Techniques Required to Build Cyanobacterial Cell Factories. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2022. [DOI: 10.1007/10_2022_210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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12
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Grohmann C, Marapana DS, Ebert G. Targeted protein degradation at the host-pathogen interface. Mol Microbiol 2021; 117:670-681. [PMID: 34816514 DOI: 10.1111/mmi.14849] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 12/24/2022]
Abstract
Infectious diseases remain a major burden to global health. Despite the implementation of successful vaccination campaigns and efficient drugs, the increasing emergence of pathogenic vaccine or treatment resistance demands novel therapeutic strategies. The development of traditional therapies using small-molecule drugs is based on modulating protein function and activity through the occupation of active sites such as enzyme inhibition or ligand-receptor binding. These prerequisites result in the majority of host and pathogenic disease-relevant, nonenzymatic and structural proteins being labeled "undruggable." Targeted protein degradation (TPD) emerged as a powerful strategy to eliminate proteins of interest including those of the undruggable variety. Proteolysis-targeting chimeras (PROTACs) are rationally designed heterobifunctional small molecules that exploit the cellular ubiquitin-proteasome system to specifically mediate the highly selective and effective degradation of target proteins. PROTACs have shown remarkable results in the degradation of various cancer-associated proteins, and several candidates are already in clinical development. Significantly, PROTAC-mediated TPD holds great potential for targeting and modulating pathogenic proteins, especially in the face of increasing drug resistance to the best-in-class treatments. In this review, we discuss advances in the development of TPD in the context of targeting the host-pathogen interface and speculate on their potential use to combat viral, bacterial, and parasitic infection.
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Affiliation(s)
- Christoph Grohmann
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Danushka S Marapana
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Gregor Ebert
- Institute of Virology, Technical University of Munich/Helmholtz Zentrum München, Munich, Germany
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13
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Gao C, Guo L, Hu G, Liu J, Chen X, Xia X, Liu L. Engineering a CRISPRi Circuit for Autonomous Control of Metabolic Flux in Escherichia coli. ACS Synth Biol 2021; 10:2661-2671. [PMID: 34609846 DOI: 10.1021/acssynbio.1c00294] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Building autonomous switches is an effective approach for rewiring metabolic flux during microbial synthesis of chemicals. However, current autonomous switches largely rely on metabolite-responsive biosensors or quorum-sensing circuits. In this study, a stationary phase promoter (SPP) and a protein degradation tag (PDT) were combined with the CRISPR interference (CRISPRi) system to construct an autonomous repression system that could shut down multiple-gene expression depending on the cellular physiological state. With this autonomous CRISPRi system to regulate one target gene, a fermenter-scale titer of shikimic acid reached 21 g/L, which was the highest titer ever reported by Escherichia coli in a minimal medium without any chemical inducers. With three target genes repressed, 26 g/L glutaric acid could be achieved with decreased byproduct accumulation. These results highlight the applicability of the autonomous CRISPRi system for microbial production of value-added chemicals.
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Affiliation(s)
- Cong Gao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China
| | - Liang Guo
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China
| | - Guipeng Hu
- School of Pharmaceutical Science, Jiangnan University, Wuxi 214122, China
| | - Jia Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China
| | - Xiulai Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China
| | - Xiaoxia Xia
- State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Liming Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China
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14
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Klimecka MM, Antosiewicz A, Izert MA, Szybowska PE, Twardowski PK, Delaunay C, Górna MW. A Uniform Benchmark for Testing SsrA-Derived Degrons in the Escherichia coli ClpXP Degradation Pathway. Molecules 2021; 26:molecules26195936. [PMID: 34641479 PMCID: PMC8512704 DOI: 10.3390/molecules26195936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 09/23/2021] [Accepted: 09/24/2021] [Indexed: 11/16/2022] Open
Abstract
The ssrA degron is commonly used in fusion proteins to control protein stability in bacteria or as an interaction module. These applications often rely on the modular activities of the ssrA tag in binding to the SspB adaptor and in engaging the ClpXP protease. However, a comparison of these activities for a substantial standard set of degron variants has not been conducted previously, which may hinder the development of new variants optimized exclusively for one application. Here, we strive to establish a benchmark that will facilitate the comparison of ssrA variants under uniform conditions. In our workflow, we included methods for expression and purification of ClpX, ClpP, SspB and eGFP-degrons, assays of ClpX ATPase activity, of eGFP-degron binding to SspB and for measuring eGFP-degron degradation in vitro and in vivo. Using uniform, precise and sensitive methods under the same conditions on a range of eGFP-degrons allowed us to determine subtle differences in their properties that can affect their potential applications. Our findings can serve as a reference and a resource for developing targeted protein degradation approaches.
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15
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Powell M, Blaskovich MAT, Hansford KA. Targeted Protein Degradation: The New Frontier of Antimicrobial Discovery? ACS Infect Dis 2021; 7:2050-2067. [PMID: 34259518 DOI: 10.1021/acsinfecdis.1c00203] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Targeted protein degradation aims to hijack endogenous protein quality control systems to achieve direct knockdown of protein targets. This exciting technology utilizes event-based pharmacology to produce therapeutic outcomes, a feature that distinguishes it from classical occupancy-based inhibitor agents. Early degrader candidates display resilience to mutations while possessing potent nanomolar activity and high target specificity. Paired with the rapid advancement of our knowledge in the factors driving targeted degradation, the expansion of this style of therapeutic agent to a range of disease indications is eagerly awaited. In particular, the area of antibiotic discovery is sorely lacking in novel approaches, with the Antimicrobial Resistance (AMR) crisis looming as the next potential global health calamity. Here, the current advances in targeted protein degradation are highlighted, and potential approaches for designing novel antimicrobial protein degraders are proposed, ranging from adaptations of current strategies to completely novel approaches to targeted protein degradation.
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Affiliation(s)
- Matthew Powell
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Mark A. T. Blaskovich
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Karl A. Hansford
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
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Wei N, Song L, Gan N. Quantitative Proteomic and Microcystin Production Response of Microcystis aeruginosa to Phosphorus Depletion. Microorganisms 2021; 9:microorganisms9061183. [PMID: 34072711 PMCID: PMC8227402 DOI: 10.3390/microorganisms9061183] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/21/2021] [Accepted: 05/25/2021] [Indexed: 12/20/2022] Open
Abstract
Microcystis blooms are the most widely distributed and frequently occurring cyanobacterial blooms in freshwater. Reducing phosphorus is suggested to be effective in mitigating cyanobacterial blooms, while the underlying molecular mechanisms are yet to be elucidated. In the present study, isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomics was employed to study the effects of phosphorus depletion on Microcystis aeruginosa FACHB-905. The production of microcystins (MCs), a severe hazard of Microcystis blooms, was also analyzed. In total, 230 proteins were found to be differentially abundant, with 136 downregulated proteins. The results revealed that, upon phosphorus limitation stress, Microcystis aeruginosa FACHB-905 raised the availability of phosphorus primarily by upregulating the expression of orthophosphate transport system proteins, with no alkaline phosphatase producing ability. Phosphorus depletion remarkably inhibited cell growth and the primary metabolic processes of Microcystis, including transcription, translation and photosynthesis, with structures of photosystems remaining intact. Moreover, expression of nitrogen assimilation proteins was downregulated, while proteins involved in carbon catabolism were significantly upregulated, which was considered beneficial for the intracellular balance among carbon, nitrogen and phosphorus. The expression of MC synthetase was not significantly different upon phosphorus depletion, while MC content was significantly suppressed. It is assumed that phosphorus depletion indirectly regulates the production of MC by the inhibition of metabolic processes and energy production. These results contribute to further understanding of the influence mechanisms of phosphorus depletion on both biological processes and MC production in Microcystis cells.
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Affiliation(s)
- Nian Wei
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China;
- Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430072, China
| | - Lirong Song
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China;
- Correspondence: (L.S.); (N.G.)
| | - Nanqin Gan
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China;
- Correspondence: (L.S.); (N.G.)
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Izert MA, Klimecka MM, Górna MW. Applications of Bacterial Degrons and Degraders - Toward Targeted Protein Degradation in Bacteria. Front Mol Biosci 2021; 8:669762. [PMID: 34026843 PMCID: PMC8138137 DOI: 10.3389/fmolb.2021.669762] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/15/2021] [Indexed: 12/28/2022] Open
Abstract
A repertoire of proteolysis-targeting signals known as degrons is a necessary component of protein homeostasis in every living cell. In bacteria, degrons can be used in place of chemical genetics approaches to interrogate and control protein function. Here, we provide a comprehensive review of synthetic applications of degrons in targeted proteolysis in bacteria. We describe recent advances ranging from large screens employing tunable degradation systems and orthogonal degrons, to sophisticated tools and sensors for imaging. Based on the success of proteolysis-targeting chimeras as an emerging paradigm in cancer drug discovery, we discuss perspectives on using bacterial degraders for studying protein function and as novel antimicrobials.
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Affiliation(s)
| | | | - Maria Wiktoria Górna
- Structural Biology Group, Biological and Chemical Research Centre, Department of Chemistry, University of Warsaw, Warsaw, Poland
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Structural determinants of regulated proteolysis in pathogenic bacteria by ClpP and the proteasome. Curr Opin Struct Biol 2021; 67:120-126. [PMID: 33221704 PMCID: PMC8096641 DOI: 10.1016/j.sbi.2020.09.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 09/25/2020] [Accepted: 09/28/2020] [Indexed: 01/05/2023]
Abstract
Bacteria use gated proteolytic machines for routine protein quality control and regulated responses to environmental conditions. This review discusses recent advances in understanding the structure and regulation of ClpP proteases, nanomachines widely distributed across bacteria, and the bacterial proteasome, a protease found in relatively few species. For both machines, activators confer substrate specificity. We highlight new data from organisms encoding two ClpP isoforms and the central role of activators as platforms for integrating regulatory signals. Because proteolytic systems contribute to survival and virulence of many bacterial pathogens, understanding their forms and functions enables new approaches to design targeted therapeutics.
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Proteasome in action: substrate degradation by the 26S proteasome. Biochem Soc Trans 2021; 49:629-644. [PMID: 33729481 PMCID: PMC8106498 DOI: 10.1042/bst20200382] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/22/2021] [Accepted: 02/25/2021] [Indexed: 12/16/2022]
Abstract
Ubiquitination is the major criteria for the recognition of a substrate-protein by the 26S proteasome. Additionally, a disordered segment on the substrate — either intrinsic or induced — is critical for proteasome engagement. The proteasome is geared to interact with both of these substrate features and prepare it for degradation. To facilitate substrate accessibility, resting proteasomes are characterised by a peripheral distribution of ubiquitin receptors on the 19S regulatory particle (RP) and a wide-open lateral surface on the ATPase ring. In this substrate accepting state, the internal channel through the ATPase ring is discontinuous, thereby obstructing translocation of potential substrates. The binding of the conjugated ubiquitin to the ubiquitin receptors leads to contraction of the 19S RP. Next, the ATPases engage the substrate at a disordered segment, energetically unravel the polypeptide and translocate it towards the 20S catalytic core (CP). In this substrate engaged state, Rpn11 is repositioned at the pore of the ATPase channel to remove remaining ubiquitin modifications and accelerate translocation. C-termini of five of the six ATPases insert into corresponding lysine-pockets on the 20S α-ring to complete 20S CP gate opening. In the resulting substrate processing state, the ATPase channel is fully contiguous with the translocation channel into the 20S CP, where the substrate is proteolyzed. Complete degradation of a typical ubiquitin-conjugate takes place over a few tens of seconds while hydrolysing tens of ATP molecules in the process (50 kDa/∼50 s/∼80ATP). This article reviews recent insight into biochemical and structural features that underlie substrate recognition and processing by the 26S proteasome.
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Programmed Proteolysis of Chemotaxis Proteins in Sinorhizobium meliloti: Features in the C-Terminal Region Control McpU Degradation. J Bacteriol 2020; 202:JB.00124-20. [PMID: 32571966 DOI: 10.1128/jb.00124-20] [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: 03/09/2020] [Accepted: 06/12/2020] [Indexed: 11/20/2022] Open
Abstract
Chemotaxis and motility are important traits that support bacterial survival in various ecological niches and in pathogenic and symbiotic host interaction. Chemotactic stimuli are sensed by chemoreceptors or methyl-accepting chemotaxis proteins (MCPs), which direct the swimming behavior of the bacterial cell. In this study, we present evidence that the cellular abundance of chemoreceptors in the plant symbiont Sinorhizobium meliloti can be altered by the addition of several to as few as one amino acid residues and by including common epitope tags such as 3×FLAG and 6×His at their C termini. To further dissect this phenomenon and its underlying molecular mechanism, we focused on a detailed analysis of the amino acid sensor McpU. Controlled proteolysis is important for the maintenance of an appropriate stoichiometry of chemoreceptors and between chemoreceptors and chemotactic signaling proteins, which is essential for an optimal chemotactic response. We hypothesized that enhanced stability is due to interference with protease binding, thus affecting proteolytic efficacy. Location of the protease recognition site was defined through McpU stability measurements in a series of deletion and amino acid substitution mutants. Deletions in the putative protease recognition site had similar effects on McpU abundance, as did extensions at the C terminus. Our results provide evidence that the programmed proteolysis of chemotaxis proteins in S. meliloti is cell cycle regulated. This posttranslational control, together with regulatory pathways on the transcriptional level, limits the chemotaxis machinery to the early exponential growth phase. Our study identified parallels to cell cycle-dependent processes during asymmetric cell division in Caulobacter crescentus IMPORTANCE The symbiotic bacterium Sinorhizobium meliloti contributes greatly to growth of the agriculturally valuable host plant alfalfa by fixing atmospheric nitrogen. Chemotaxis of S. meliloti cells toward alfalfa roots mediates this symbiosis. The present study establishes programmed proteolysis as a factor in the maintenance of the S. meliloti chemotaxis system. Knowledge about cell cycle-dependent, targeted, and selective proteolysis in S. meliloti is important to understand the molecular mechanisms of maintaining a suitable chemotaxis response. While the role of regulated protein turnover in the cell cycle progression of Caulobacter crescentus is well understood, these pathways are just beginning to be characterized in S. meliloti In addition, our study should alert about the cautionary use of epitope tags for protein quantification.
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