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Max L Nibert - One of the best experts on this subject based on the ideXlab platform.
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Three-Dimensional Structure of a Protozoal Double-Stranded RNA Virus That Infects the Enteric Pathogen Giardia Lamblia
Journal of Virology, 2014Co-Authors: Mandy E.w. Janssen, Yuko Takagi, Giovanni Cardone, Kristin N. Parent, Max L Nibert, Timothy S. BakerAbstract:Giardia Lamblia Virus (GLV) is a small, nonenveloped, nonsegmented double-stranded RNA (dsRNA) Virus infecting Giardia Lamblia, the most common protozoan pathogen of the human intestine and a major agent of waterborne diarrheal disease worldwide. GLV (genus GiardiaVirus) is a member of family Totiviridae, along with several other groups of protozoal or fungal Viruses, including Leishmania RNA Viruses and Trichomonas vaginalis Viruses. Interestingly, GLV is more closely related than other Totiviridae members to a group of recently discovered metazoan Viruses that includes penaeid shrimp infectious myonecrosis Virus (IMNV). Moreover, GLV is the only known protozoal dsRNA Virus that can transmit efficiently by extracellular means, also like IMNV. In this study, we used transmission electron cryomicroscopy and icosahedral image reconstruction to examine the GLV virion at an estimated resolution of 6.0 Å. Its outermost diameter is 485 Å, making it the largest totiVirus capsid analyzed to date. Structural comparisons of GLV and other totiViruses highlighted a related “T=2” capsid organization and a conserved helix-rich fold in the capsid subunits. In agreement with its unique capacity as a protozoal dsRNA Virus to survive and transmit through extracellular environments, GLV was found to be more thermoresistant than Trichomonas vaginalis Virus 1, but no specific protein machinery to mediate cell entry, such as the fiber complexes in IMNV, could be localized. These and other structural and biochemical findings provide a basis for future work to dissect the cell entry mechanism of GLV into a “primitive” (early-branching) eukaryotic host and an important enteric pathogen of humans. IMPORTANCE Numerous pathogenic bacteria, including Corynebacterium diphtheriae, Salmonella enterica, and Vibrio cholerae, are infected with lysogenic bacteriophages that contribute significantly to bacterial virulence. In line with this phenomenon, several pathogenic protozoa, including Giardia Lamblia, Leishmania species, and Trichomonas vaginalis are persistently infected with dsRNA Viruses, and growing evidence indicates that at least some of these protozoal Viruses can likewise enhance the pathogenicity of their hosts. Understanding of these protozoal Viruses, however, lags far behind that of many bacteriophages. Here, we investigated the dsRNA Virus that infects the widespread enteric parasite Giardia Lamblia. Using electron cryomicroscopy and icosahedral image reconstruction, we determined the virion structure of Giardia Lamblia Virus, obtaining new information relating to its assembly, stability, functions in cell entry and transcription, and similarities and differences with other dsRNA Viruses. The results of our study set the stage for further mechanistic work on the roles of these Viruses in protozoal virulence.
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The Three-Dimensional Structure of Giardia Lamblia Virus and its Comparison to Other Members of the Family Totiviridae
Microscopy and Microanalysis, 2013Co-Authors: Mandy E.w. Janssen, Yuko Takagi, Kristin N. Parent, Max L Nibert, Timothy S. BakerAbstract:Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.
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‘2A-like’ and ‘shifty heptamer’ motifs in penaeid shrimp infectious myonecrosis Virus, a monosegmented double-stranded RNA Virus
Journal of General Virology, 2007Co-Authors: Max L NibertAbstract:Penaeid shrimp infectious myonecrosis Virus (IMNV) is a monosegmented double-stranded RNA Virus that forms icosahedral virions and is tentatively assigned to the family Totiviridae. New examinations of the IMNV genome sequence revealed features not noted in the original report. These features include (i) two encoded '2A-like' motifs, which are likely involved in open reading frame (ORF) 1 polyprotein 'cleavage'; (ii) a 199 nt overlap between the end of ORF1 in frame 1 and the start of ORF2 in frame 3; and (iii) a 'shifty heptamer' motif and predicted RNA pseudoknot in the region of ORF1-ORF2 overlap, which probably allow ORF2 to be translated as a fusion with ORF1 by -1 ribosomal frameshifting. Features (ii) and (iii) bring the predicted ORF2 coding strategy of IMNV more in line with that of its closest phylogenetic relative, Giardia Lamblia Virus, as well as with that of several other members of the family Totiviridae including Saccharomyces cerevisiae Virus L-A.
Timothy S. Baker - One of the best experts on this subject based on the ideXlab platform.
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Three-Dimensional Structure of a Protozoal Double-Stranded RNA Virus That Infects the Enteric Pathogen Giardia Lamblia
Journal of Virology, 2014Co-Authors: Mandy E.w. Janssen, Yuko Takagi, Giovanni Cardone, Kristin N. Parent, Max L Nibert, Timothy S. BakerAbstract:Giardia Lamblia Virus (GLV) is a small, nonenveloped, nonsegmented double-stranded RNA (dsRNA) Virus infecting Giardia Lamblia, the most common protozoan pathogen of the human intestine and a major agent of waterborne diarrheal disease worldwide. GLV (genus GiardiaVirus) is a member of family Totiviridae, along with several other groups of protozoal or fungal Viruses, including Leishmania RNA Viruses and Trichomonas vaginalis Viruses. Interestingly, GLV is more closely related than other Totiviridae members to a group of recently discovered metazoan Viruses that includes penaeid shrimp infectious myonecrosis Virus (IMNV). Moreover, GLV is the only known protozoal dsRNA Virus that can transmit efficiently by extracellular means, also like IMNV. In this study, we used transmission electron cryomicroscopy and icosahedral image reconstruction to examine the GLV virion at an estimated resolution of 6.0 Å. Its outermost diameter is 485 Å, making it the largest totiVirus capsid analyzed to date. Structural comparisons of GLV and other totiViruses highlighted a related “T=2” capsid organization and a conserved helix-rich fold in the capsid subunits. In agreement with its unique capacity as a protozoal dsRNA Virus to survive and transmit through extracellular environments, GLV was found to be more thermoresistant than Trichomonas vaginalis Virus 1, but no specific protein machinery to mediate cell entry, such as the fiber complexes in IMNV, could be localized. These and other structural and biochemical findings provide a basis for future work to dissect the cell entry mechanism of GLV into a “primitive” (early-branching) eukaryotic host and an important enteric pathogen of humans. IMPORTANCE Numerous pathogenic bacteria, including Corynebacterium diphtheriae, Salmonella enterica, and Vibrio cholerae, are infected with lysogenic bacteriophages that contribute significantly to bacterial virulence. In line with this phenomenon, several pathogenic protozoa, including Giardia Lamblia, Leishmania species, and Trichomonas vaginalis are persistently infected with dsRNA Viruses, and growing evidence indicates that at least some of these protozoal Viruses can likewise enhance the pathogenicity of their hosts. Understanding of these protozoal Viruses, however, lags far behind that of many bacteriophages. Here, we investigated the dsRNA Virus that infects the widespread enteric parasite Giardia Lamblia. Using electron cryomicroscopy and icosahedral image reconstruction, we determined the virion structure of Giardia Lamblia Virus, obtaining new information relating to its assembly, stability, functions in cell entry and transcription, and similarities and differences with other dsRNA Viruses. The results of our study set the stage for further mechanistic work on the roles of these Viruses in protozoal virulence.
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The Three-Dimensional Structure of Giardia Lamblia Virus and its Comparison to Other Members of the Family Totiviridae
Microscopy and Microanalysis, 2013Co-Authors: Mandy E.w. Janssen, Yuko Takagi, Kristin N. Parent, Max L Nibert, Timothy S. BakerAbstract:Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.
Mandy E.w. Janssen - One of the best experts on this subject based on the ideXlab platform.
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Three-dimensional structure of a protozoal double-stranded RNA Virus that infects the enteric pathogen Giardia Lamblia.
eScholarship University of California, 2015Co-Authors: Mandy E.w. Janssen, Takagi Yuko, Parent, Kristin N, Cardone Giovanni, Nibert, Max L, Baker, Timothy SAbstract:Giardia Lamblia Virus (GLV) is a small, nonenveloped, nonsegmented double-stranded RNA (dsRNA) Virus infecting Giardia Lamblia, the most common protozoan pathogen of the human intestine and a major agent of waterborne diarrheal disease worldwide. GLV (genus GiardiaVirus) is a member of family Totiviridae, along with several other groups of protozoal or fungal Viruses, including Leishmania RNA Viruses and Trichomonas vaginalis Viruses. Interestingly, GLV is more closely related than other Totiviridae members to a group of recently discovered metazoan Viruses that includes penaeid shrimp infectious myonecrosis Virus (IMNV). Moreover, GLV is the only known protozoal dsRNA Virus that can transmit efficiently by extracellular means, also like IMNV. In this study, we used transmission electron cryomicroscopy and icosahedral image reconstruction to examine the GLV virion at an estimated resolution of 6.0 Å. Its outermost diameter is 485 Å, making it the largest totiVirus capsid analyzed to date. Structural comparisons of GLV and other totiViruses highlighted a related "T=2" capsid organization and a conserved helix-rich fold in the capsid subunits. In agreement with its unique capacity as a protozoal dsRNA Virus to survive and transmit through extracellular environments, GLV was found to be more thermoresistant than Trichomonas vaginalis Virus 1, but no specific protein machinery to mediate cell entry, such as the fiber complexes in IMNV, could be localized. These and other structural and biochemical findings provide a basis for future work to dissect the cell entry mechanism of GLV into a "primitive" (early-branching) eukaryotic host and an important enteric pathogen of humans.Numerous pathogenic bacteria, including Corynebacterium diphtheriae, Salmonella enterica, and Vibrio cholerae, are infected with lysogenic bacteriophages that contribute significantly to bacterial virulence. In line with this phenomenon, several pathogenic protozoa, including Giardia Lamblia, Leishmania species, and Trichomonas vaginalis are persistently infected with dsRNA Viruses, and growing evidence indicates that at least some of these protozoal Viruses can likewise enhance the pathogenicity of their hosts. Understanding of these protozoal Viruses, however, lags far behind that of many bacteriophages. Here, we investigated the dsRNA Virus that infects the widespread enteric parasite Giardia Lamblia. Using electron cryomicroscopy and icosahedral image reconstruction, we determined the virion structure of Giardia Lamblia Virus, obtaining new information relating to its assembly, stability, functions in cell entry and transcription, and similarities and differences with other dsRNA Viruses. The results of our study set the stage for further mechanistic work on the roles of these Viruses in protozoal virulence
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Three-Dimensional Structure of a Protozoal Double-Stranded RNA Virus That Infects the Enteric Pathogen Giardia Lamblia
Journal of Virology, 2014Co-Authors: Mandy E.w. Janssen, Yuko Takagi, Giovanni Cardone, Kristin N. Parent, Max L Nibert, Timothy S. BakerAbstract:Giardia Lamblia Virus (GLV) is a small, nonenveloped, nonsegmented double-stranded RNA (dsRNA) Virus infecting Giardia Lamblia, the most common protozoan pathogen of the human intestine and a major agent of waterborne diarrheal disease worldwide. GLV (genus GiardiaVirus) is a member of family Totiviridae, along with several other groups of protozoal or fungal Viruses, including Leishmania RNA Viruses and Trichomonas vaginalis Viruses. Interestingly, GLV is more closely related than other Totiviridae members to a group of recently discovered metazoan Viruses that includes penaeid shrimp infectious myonecrosis Virus (IMNV). Moreover, GLV is the only known protozoal dsRNA Virus that can transmit efficiently by extracellular means, also like IMNV. In this study, we used transmission electron cryomicroscopy and icosahedral image reconstruction to examine the GLV virion at an estimated resolution of 6.0 Å. Its outermost diameter is 485 Å, making it the largest totiVirus capsid analyzed to date. Structural comparisons of GLV and other totiViruses highlighted a related “T=2” capsid organization and a conserved helix-rich fold in the capsid subunits. In agreement with its unique capacity as a protozoal dsRNA Virus to survive and transmit through extracellular environments, GLV was found to be more thermoresistant than Trichomonas vaginalis Virus 1, but no specific protein machinery to mediate cell entry, such as the fiber complexes in IMNV, could be localized. These and other structural and biochemical findings provide a basis for future work to dissect the cell entry mechanism of GLV into a “primitive” (early-branching) eukaryotic host and an important enteric pathogen of humans. IMPORTANCE Numerous pathogenic bacteria, including Corynebacterium diphtheriae, Salmonella enterica, and Vibrio cholerae, are infected with lysogenic bacteriophages that contribute significantly to bacterial virulence. In line with this phenomenon, several pathogenic protozoa, including Giardia Lamblia, Leishmania species, and Trichomonas vaginalis are persistently infected with dsRNA Viruses, and growing evidence indicates that at least some of these protozoal Viruses can likewise enhance the pathogenicity of their hosts. Understanding of these protozoal Viruses, however, lags far behind that of many bacteriophages. Here, we investigated the dsRNA Virus that infects the widespread enteric parasite Giardia Lamblia. Using electron cryomicroscopy and icosahedral image reconstruction, we determined the virion structure of Giardia Lamblia Virus, obtaining new information relating to its assembly, stability, functions in cell entry and transcription, and similarities and differences with other dsRNA Viruses. The results of our study set the stage for further mechanistic work on the roles of these Viruses in protozoal virulence.
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The Three-Dimensional Structure of Giardia Lamblia Virus and its Comparison to Other Members of the Family Totiviridae
Microscopy and Microanalysis, 2013Co-Authors: Mandy E.w. Janssen, Yuko Takagi, Kristin N. Parent, Max L Nibert, Timothy S. BakerAbstract:Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.
Donald V Lightner - One of the best experts on this subject based on the ideXlab platform.
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purification and characterization of infectious myonecrosis Virus of penaeid shrimp
Journal of General Virology, 2006Co-Authors: Bonnie T Poulos, Kathy F J Tang, Carlos R Pantoja, Jean Robert Bonami, Donald V LightnerAbstract:The causative agent of myonecrosis affecting cultured Penaeus vannamei in Brazil was demonstrated to be a Virus after purification of the agent from infected shrimp tissues. Purified viral particles were injected into specific pathogen-free P. vannamei, resulting in a disease that displayed the same characteristics as those found in the original shrimp used for purification. The Virus was named infectious myonecrosis Virus (IMNV). The viral particles were icosahedral in shape and 40 nm in diameter, with a buoyant density of 1(.)366 g ml(-1) in caesium chloride. The genome consisted of a single, double-stranded (dsRNA) molecule of 7560 bp. Sequencing of the viral genome revealed two non-overlapping open reading frames (ORFs). The 5' ORF (ORF 1, nt 136-4953) encoded a putative RNA-binding protein and a capsid protein. The coding region of the RNA-binding protein was located in the first half of ORF 1 and contained a dsRNA-binding motif in the first 60 aa. The second half of ORF 1 encoded a capsid protein, as determined by amino acid sequencing, with a molecular mass of 106 kDa. The 3' ORF (ORF 2, nt 5241-7451) encoded a putative RNA-dependent RNA polymerase (RdRp) with motifs characteristic of totiViruses. Phylogenetic analysis based on the RdRp clustered IMNV with Giardia Lamblia Virus, a member of the family Totiviridae. Based on these findings, IMNV may be unique member of the Totiviridae or may represent a new dsRNA Virus family that infects invertebrate hosts.
Kristin N. Parent - One of the best experts on this subject based on the ideXlab platform.
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Three-Dimensional Structure of a Protozoal Double-Stranded RNA Virus That Infects the Enteric Pathogen Giardia Lamblia
Journal of Virology, 2014Co-Authors: Mandy E.w. Janssen, Yuko Takagi, Giovanni Cardone, Kristin N. Parent, Max L Nibert, Timothy S. BakerAbstract:Giardia Lamblia Virus (GLV) is a small, nonenveloped, nonsegmented double-stranded RNA (dsRNA) Virus infecting Giardia Lamblia, the most common protozoan pathogen of the human intestine and a major agent of waterborne diarrheal disease worldwide. GLV (genus GiardiaVirus) is a member of family Totiviridae, along with several other groups of protozoal or fungal Viruses, including Leishmania RNA Viruses and Trichomonas vaginalis Viruses. Interestingly, GLV is more closely related than other Totiviridae members to a group of recently discovered metazoan Viruses that includes penaeid shrimp infectious myonecrosis Virus (IMNV). Moreover, GLV is the only known protozoal dsRNA Virus that can transmit efficiently by extracellular means, also like IMNV. In this study, we used transmission electron cryomicroscopy and icosahedral image reconstruction to examine the GLV virion at an estimated resolution of 6.0 Å. Its outermost diameter is 485 Å, making it the largest totiVirus capsid analyzed to date. Structural comparisons of GLV and other totiViruses highlighted a related “T=2” capsid organization and a conserved helix-rich fold in the capsid subunits. In agreement with its unique capacity as a protozoal dsRNA Virus to survive and transmit through extracellular environments, GLV was found to be more thermoresistant than Trichomonas vaginalis Virus 1, but no specific protein machinery to mediate cell entry, such as the fiber complexes in IMNV, could be localized. These and other structural and biochemical findings provide a basis for future work to dissect the cell entry mechanism of GLV into a “primitive” (early-branching) eukaryotic host and an important enteric pathogen of humans. IMPORTANCE Numerous pathogenic bacteria, including Corynebacterium diphtheriae, Salmonella enterica, and Vibrio cholerae, are infected with lysogenic bacteriophages that contribute significantly to bacterial virulence. In line with this phenomenon, several pathogenic protozoa, including Giardia Lamblia, Leishmania species, and Trichomonas vaginalis are persistently infected with dsRNA Viruses, and growing evidence indicates that at least some of these protozoal Viruses can likewise enhance the pathogenicity of their hosts. Understanding of these protozoal Viruses, however, lags far behind that of many bacteriophages. Here, we investigated the dsRNA Virus that infects the widespread enteric parasite Giardia Lamblia. Using electron cryomicroscopy and icosahedral image reconstruction, we determined the virion structure of Giardia Lamblia Virus, obtaining new information relating to its assembly, stability, functions in cell entry and transcription, and similarities and differences with other dsRNA Viruses. The results of our study set the stage for further mechanistic work on the roles of these Viruses in protozoal virulence.
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The Three-Dimensional Structure of Giardia Lamblia Virus and its Comparison to Other Members of the Family Totiviridae
Microscopy and Microanalysis, 2013Co-Authors: Mandy E.w. Janssen, Yuko Takagi, Kristin N. Parent, Max L Nibert, Timothy S. BakerAbstract:Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.