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Horovitz A, Azem A. Editorial: A focus on chaperone clients. Front Mol Biosci 2023; 10:1180739. [PMID: 37006613 PMCID: PMC10064806 DOI: 10.3389/fmolb.2023.1180739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 03/19/2023] Open
Affiliation(s)
- Amnon Horovitz
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
- *Correspondence: Amnon Horovitz,
| | - Abdussalam Azem
- School of Neurobiology, Biochemistry and Biophysics, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
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Bhatt JM, Enriquez AS, Wang J, Rojo HM, Molugu SK, Hildenbrand ZL, Bernal RA. Single-Ring Intermediates Are Essential for Some Chaperonins. Front Mol Biosci 2018; 5:42. [PMID: 29755985 PMCID: PMC5934643 DOI: 10.3389/fmolb.2018.00042] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 04/13/2018] [Indexed: 11/20/2022] Open
Abstract
Chaperonins are macromolecular complexes found throughout all kingdoms of life that assist unfolded proteins reach a biologically active state. Historically, chaperonins have been classified into two groups based on sequence, subunit structure, and the requirement for a co-chaperonin. Here, we present a brief review of chaperonins that can form double- and single-ring conformational intermediates in their protein-folding catalytic pathway. To date, the bacteriophage encoded chaperonins ϕ-EL and OBP, human mitochondrial chaperonin and most recently, the bacterial groEL/ES systems, have been reported to form single-ring intermediates as part of their normal protein-folding activity. These double-ring chaperonins separate into single-ring intermediates that have the ability to independently fold a protein. We discuss the structural and functional features along with the biological relevance of single-ring intermediates in cellular protein folding. Of special interest are the ϕ-EL and OBP chaperonins which demonstrate features of both group I and II chaperonins in addition to their ability to function via single-ring intermediates.
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Affiliation(s)
- Jay M Bhatt
- Department of Chemistry, The University of Texas at El Paso, El Paso, TX, United States
| | - Adrian S Enriquez
- Department of Chemistry, The University of Texas at El Paso, El Paso, TX, United States
| | - Jinliang Wang
- Department of Chemistry, The University of Texas at El Paso, El Paso, TX, United States
| | - Humberto M Rojo
- Department of Chemistry, The University of Texas at El Paso, El Paso, TX, United States
| | - Sudheer K Molugu
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | | | - Ricardo A Bernal
- Department of Chemistry, The University of Texas at El Paso, El Paso, TX, United States
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Abstract
Xanthomonas virus (phage) XacN1 is a novel jumbo myovirus infecting Xanthomonas citri, the causative agent of Asian citrus canker. Its linear 384,670 bp double-stranded DNA genome encodes 592 proteins and presents the longest (66 kbp) direct terminal repeats (DTRs) among sequenced viral genomes. The DTRs harbor 56 tRNA genes, which correspond to all 20 amino acids and represent the largest number of tRNA genes reported in a viral genome. Codon usage analysis revealed a propensity for the phage encoded tRNAs to target codons that are highly used by the phage but less frequently by its host. The existence of these tRNA genes and seven additional translation-related genes as well as a chaperonin gene found in the XacN1 genome suggests a relative independence of phage replication on host molecular machinery, leading to a prediction of a wide host range for this jumbo phage. We confirmed the prediction by showing a wider host range of XacN1 than other X. citri phages in an infection test against a panel of host strains. Phylogenetic analyses revealed a clade of phages composed of XacN1 and ten other jumbo phages, indicating an evolutionary stable large genome size for this group of phages.
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Enriquez AS, Rojo HM, Bhatt JM, Molugu SK, Hildenbrand ZL, Bernal RA. The human mitochondrial Hsp60 in the APO conformation forms a stable tetradecameric complex. Cell Cycle 2017; 16:1309-1319. [PMID: 28594255 PMCID: PMC5531633 DOI: 10.1080/15384101.2017.1321180] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
The human mitochondrial chaperonin is a macromolecular machine that catalyzes the proper folding of mitochondrial proteins and is of vital importance to all cells. This chaperonin is composed of 2 distinct proteins, Hsp60 and Hsp10, that assemble into large oligomeric complexes that mediate the folding of non-native polypeptides in an ATP dependent manner. Here, we report the bacterial expression and purification of fully assembled human Hsp60 and Hsp10 recombinant proteins and that Hsp60 forms a stable tetradecameric double-ring conformation in the absence of co-chaperonin and nucleotide. Evidence of the stable double-ring conformation is illustrated by the 15 Å resolution electron microscopy reconstruction presented here. Furthermore, our biochemical analyses reveal that the presence of a non-native substrate initiates ATP-hydrolysis within the Hsp60/10 chaperonin to commence protein folding. Collectively, these data provide insight into the architecture of the intermediates used by the human mitochondrial chaperonin along its protein folding pathway and lay a foundation for subsequent high resolution structural investigations into the conformational changes of the mitochondrial chaperonin.
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Affiliation(s)
- Adrian S Enriquez
- a Department of Chemistry , The University of Texas at El Paso , El Paso , TX , USA
| | - Humberto M Rojo
- a Department of Chemistry , The University of Texas at El Paso , El Paso , TX , USA
| | - Jay M Bhatt
- a Department of Chemistry , The University of Texas at El Paso , El Paso , TX , USA
| | - Sudheer K Molugu
- b Department of Pharmacology , School of Medicine, Case Western Reserve University , Cleveland , OH , USA
| | | | - Ricardo A Bernal
- a Department of Chemistry , The University of Texas at El Paso , El Paso , TX , USA
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Environmental Viral Genomes Shed New Light on Virus-Host Interactions in the Ocean. mSphere 2017; 2:mSphere00359-16. [PMID: 28261669 PMCID: PMC5332604 DOI: 10.1128/msphere.00359-16] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 02/02/2017] [Indexed: 11/27/2022] Open
Abstract
Viruses are diverse and play significant ecological roles in marine ecosystems. However, our knowledge of genome-level diversity in viruses is biased toward those isolated from few culturable hosts. Here, we determined 1,352 nonredundant complete viral genomes from marine environments. Lifting the uncertainty that clouds short incomplete sequences, whole-genome-wide analysis suggests that these environmental genomes represent hundreds of putative novel viral genera. Predicted hosts include dominant groups of marine bacteria and archaea with no isolated viruses to date. Some of the viral genomes encode many functionally related enzymes, suggesting a strong selection pressure on these marine viruses to control cellular metabolisms by accumulating genes. Metagenomics has revealed the existence of numerous uncharacterized viral lineages, which are referred to as viral “dark matter.” However, our knowledge regarding viral genomes is biased toward culturable viruses. In this study, we analyzed 1,600 (1,352 nonredundant) complete double-stranded DNA viral genomes (10 to 211 kb) assembled from 52 marine viromes. Together with 244 previously reported uncultured viral genomes, a genome-wide comparison delineated 617 genus-level operational taxonomic units (OTUs) for these environmental viral genomes (EVGs). Of these, 600 OTUs contained no representatives from known viruses, thus putatively corresponding to novel viral genera. Predicted hosts of the EVGs included major groups of marine prokaryotes, such as marine group II Euryarchaeota and SAR86, from which no viruses have been isolated to date, as well as Flavobacteriaceae and SAR116. Our analysis indicates that marine cyanophages are already well represented in genome databases and that one of the EVGs likely represents a new cyanophage lineage. Several EVGs encode many enzymes that appear to function for an efficient utilization of iron-sulfur clusters or to enhance host survival. This suggests that there is a selection pressure on these marine viruses to accumulate genes for specific viral propagation strategies. Finally, we revealed that EVGs contribute to a 4-fold increase in the recruitment of photic-zone viromes compared with the use of current reference viral genomes. IMPORTANCE Viruses are diverse and play significant ecological roles in marine ecosystems. However, our knowledge of genome-level diversity in viruses is biased toward those isolated from few culturable hosts. Here, we determined 1,352 nonredundant complete viral genomes from marine environments. Lifting the uncertainty that clouds short incomplete sequences, whole-genome-wide analysis suggests that these environmental genomes represent hundreds of putative novel viral genera. Predicted hosts include dominant groups of marine bacteria and archaea with no isolated viruses to date. Some of the viral genomes encode many functionally related enzymes, suggesting a strong selection pressure on these marine viruses to control cellular metabolisms by accumulating genes.
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den Hollander PW, de Sousa Geraldino Duarte P, Bloksma H, Boeren S, van Lent JWM. Proteomic analysis of the plasma membrane-movement tubule complex of cowpea mosaic virus. Arch Virol 2016; 161:1309-14. [PMID: 26780773 DOI: 10.1007/s00705-016-2757-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 01/08/2016] [Indexed: 10/22/2022]
Abstract
Cowpea mosaic virus forms tubules constructed from the movement protein (MP) in plasmodesmata (PD) to achieve cell-to-cell movement of its virions. Similar tubules, delineated by the plasma membrane (PM), are formed protruding from the surface of infected protoplasts. These PM-tubule complexes were isolated from protoplasts by immunoprecipitation and analysed for their protein content by tandem mass spectrometry to identify host proteins with affinity for the movement tubule. Seven host proteins were abundantly present in the PM-tubule complex, including molecular chaperonins and an AAA protein. Members of both protein families have been implicated in establishment of systemic infection. The potential role of these proteins in tubule-guided cell-cell transport is discussed.
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Affiliation(s)
- Paulus W den Hollander
- Laboratory of Virology, Plant Sciences Group, Wageningen University, Wageningen, The Netherlands
| | | | - Hanke Bloksma
- Laboratory of Virology, Plant Sciences Group, Wageningen University, Wageningen, The Netherlands
| | - Sjef Boeren
- Laboratory of Biochemistry, Agrotechnology and Food Sciences, Wageningen University, Wageningen, The Netherlands
| | - Jan W M van Lent
- Laboratory of Virology, Plant Sciences Group, Wageningen University, Wageningen, The Netherlands.
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Zhang J, Ye C, Ruan X, Zan J, Xu Y, Liao M, Zhou J. The chaperonin CCTα is required for efficient transcription and replication of rabies virus. Microbiol Immunol 2015; 58:590-9. [PMID: 25082455 DOI: 10.1111/1348-0421.12186] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 07/08/2014] [Accepted: 07/24/2014] [Indexed: 12/25/2022]
Abstract
Negri bodies (NBs) are formed in the cytoplasm of rabies virus (RABV)-infected cells and are accompanied by a number of host factors to NBs, in which replication and transcription occur. Here, it was found that chaperonin containing TCP-1 subunit alpha (CCTα) relocalizes to NBs in RABV-infected cells, and that cotransfection of nucleo- and phospho-proteins of RABV is sufficient to recruit CCTα to the NBs' structure. Inhibition of CCTα expression by specific short hairpin RNA knockdown inhibited the replication and transcription of RABV. Therefore, this study showed that the host factor CCTα is associated with RABV infection and is very likely required for efficient virus transcription and replication.
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Affiliation(s)
- Jinyang Zhang
- Key Laboratory of Animal Virology of Ministry of Agriculture, Zhejiang University, Hangzhou, 310058; State Key Laboratory and Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, Zhejiang University, Hangzhou, 310003; Research Center of Molecular Medicine of Yunnan Province, Kunming University of Science and Technology, Kunming, 650500, China
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Holmfeldt K, Solonenko N, Shah M, Corrier K, Riemann L, VerBerkmoes NC, Sullivan MB. Twelve previously unknown phage genera are ubiquitous in global oceans. Proc Natl Acad Sci U S A 2013; 110:12798-803. [PMID: 23858439 PMCID: PMC3732932 DOI: 10.1073/pnas.1305956110] [Citation(s) in RCA: 149] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Viruses are fundamental to ecosystems ranging from oceans to humans, yet our ability to study them is bottlenecked by the lack of ecologically relevant isolates, resulting in "unknowns" dominating culture-independent surveys. Here we present genomes from 31 phages infecting multiple strains of the aquatic bacterium Cellulophaga baltica (Bacteroidetes) to provide data for an underrepresented and environmentally abundant bacterial lineage. Comparative genomics delineated 12 phage groups that (i) each represent a new genus, and (ii) represent one novel and four well-known viral families. This diversity contrasts the few well-studied marine phage systems, but parallels the diversity of phages infecting human-associated bacteria. Although all 12 Cellulophaga phages represent new genera, the podoviruses and icosahedral, nontailed ssDNA phages were exceptional, with genomes up to twice as large as those previously observed for each phage type. Structural novelty was also substantial, requiring experimental phage proteomics to identify 83% of the structural proteins. The presence of uncommon nucleotide metabolism genes in four genera likely underscores the importance of scavenging nutrient-rich molecules as previously seen for phages in marine environments. Metagenomic recruitment analyses suggest that these particular Cellulophaga phages are rare and may represent a first glimpse into the phage side of the rare biosphere. However, these analyses also revealed that these phage genera are widespread, occurring in 94% of 137 investigated metagenomes. Together, this diverse and novel collection of phages identifies a small but ubiquitous fraction of unknown marine viral diversity and provides numerous environmentally relevant phage-host systems for experimental hypothesis testing.
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Affiliation(s)
- Karin Holmfeldt
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721
| | - Natalie Solonenko
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721
| | - Manesh Shah
- Chemical Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831; and
| | - Kristen Corrier
- Chemical Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831; and
| | - Lasse Riemann
- Department of Biology, University of Copenhagen, 3000 Helsingor, Denmark
| | | | - Matthew B. Sullivan
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721
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Wang Y, Zhang WY, Zhang Z, Li J, Li ZF, Tan ZG, Zhang TT, Wu ZH, Liu H, Li YZ. Mechanisms involved in the functional divergence of duplicated GroEL chaperonins in Myxococcus xanthus DK1622. PLoS Genet 2013; 9:e1003306. [PMID: 23437010 PMCID: PMC3578752 DOI: 10.1371/journal.pgen.1003306] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 12/20/2012] [Indexed: 12/24/2022] Open
Abstract
The gene encoding the GroEL chaperonin is duplicated in nearly 30% of bacterial genomes; and although duplicated groEL genes have been comprehensively determined to have distinct physiological functions in different species, the mechanisms involved have not been characterized to date. Myxococcus xanthus DK1622 has two copies of the groEL gene, each of which can be deleted without affecting cell viability; however, the deletion of either gene does result in distinct defects in the cellular heat-shock response, predation, and development. In this study, we show that, from the expression levels of different groELs, the distinct functions of groEL1 and groEL2 in predation and development are probably the result of the substrate selectivity of the paralogous GroEL chaperonins, whereas the lethal effect of heat shock due to the deletion of groEL1 is caused by a decrease in the total groEL expression level. Following a bioinformatics analysis of the composition characteristics of GroELs from different bacteria, we performed region-swapping assays in M. xanthus, demonstrating that the differences in the apical and the C-terminal equatorial regions determine the substrate specificity of the two GroELs. Site-directed mutagenesis experiments indicated that the GGM repeat sequence at the C-terminus of GroEL1 plays an important role in functional divergence. Divergent functions of duplicated GroELs, which have similar patterns of variation in different bacterial species, have thus evolved mainly via alteration of the apical and the C-terminal equatorial regions. We identified the specific substrates of strain DK1622's GroEL1 and GroEL2 using immunoprecipitation and mass spectrometry techniques. Although 68 proteins bound to both GroEL1 and GroEL2, 83 and 46 proteins bound exclusively to GroEL1 or GroEL2, respectively. The GroEL-specific substrates exhibited distinct molecular sizes and secondary structures, providing an encouraging indication for GroEL evolution for functional divergence.
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Affiliation(s)
- Yan Wang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
| | - Wen-yan Zhang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
| | - Zheng Zhang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
| | - Jian Li
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
| | - Zhi-feng Li
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
| | - Zai-gao Tan
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
| | - Tian-tian Zhang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
| | - Zhi-hong Wu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
| | - Hong Liu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
| | - Yue-zhong Li
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
- * E-mail:
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Mateu MG. Assembly, stability and dynamics of virus capsids. Arch Biochem Biophys 2012; 531:65-79. [PMID: 23142681 DOI: 10.1016/j.abb.2012.10.015] [Citation(s) in RCA: 150] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 10/18/2012] [Accepted: 10/28/2012] [Indexed: 12/13/2022]
Abstract
Most viruses use a hollow protein shell, the capsid, to enclose the viral genome. Virus capsids are large, symmetric oligomers made of many copies of one or a few types of protein subunits. Self-assembly of a viral capsid is a complex oligomerization process that proceeds along a pathway regulated by ordered interactions between the participating protein subunits, and that involves a series of (usually transient) assembly intermediates. Assembly of many virus capsids requires the assistance of scaffolding proteins or the viral nucleic acid, which interact with the capsid subunits to promote and direct the process. Once assembled, many capsids undergo a maturation reaction that involves covalent modification and/or conformational rearrangements, which may increase the stability of the particle. The final, mature capsid is a relatively robust protein complex able to protect the viral genome from physicochemical aggressions; however, it is also a metastable, dynamic structure poised to undergo controlled conformational transitions required to perform biologically critical functions during virus entry into cells, intracellular trafficking, and viral genome uncoating. This article provides an updated general overview on structural, biophysical and biochemical aspects of the assembly, stability and dynamics of virus capsids.
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Affiliation(s)
- Mauricio G Mateu
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Universidad Autónoma de Madrid, 28049 Madrid, Spain.
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