A novel pathogenicity determinant hijacks maize catalase 1 to enhance viral multiplication and infection

2021 ◽  
Author(s):  
Zhiyuan Jiao ◽  
Yiying Tian ◽  
Yanyong Cao ◽  
Juan Wang ◽  
Binhui Zhan ◽  
...  
Keyword(s):  
Viral Multiplication ◽  
Pathogenicity Determinant

A Device for Rapid Removal of Embryos from Fish Eggs

1971 ◽  
Vol 28 (1) ◽  
pp. 100-102 ◽  
Author(s):  
R. M. MacKelvie
Keyword(s):  
Fish Eggs ◽  
Viral Multiplication ◽  
Rapid Removal

An inexpensive and easily constructed device is described whereby embryos were removed from fish eggs for the study of viral multiplication.

scholarly journals A PB1-K577E Mutation in H9N2 Influenza Virus Increases Polymerase Activity and Pathogenicity in Mice

Viruses ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 653 ◽  
Author(s):  
Haruhiko Kamiki ◽  
Hiromichi Matsugo ◽  
Tomoya Kobayashi ◽  
Hiroho Ishida ◽  
Akiko Takenaka-Uema ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Novel Mutation ◽  
Polymerase Activity ◽  
Influenza Viruses ◽  
H9n2 Virus ◽  
Wild Type Virus ◽  
H9n2 Influenza Virus ◽  
Pathogenicity Determinant ◽  
Lower Temperature ◽  
Human Infections

H9N2 avian influenza viruses are present in poultry worldwide. These viruses are considered to have pandemic potential, because recent isolates can recognize human-type receptor and several sporadic human infections have been reported. In this study, we aimed to identify mutations related to mammalian adaptation of H9N2 influenza virus. We found that mouse-adapted viruses had several mutations in hemagglutinin (HA), PB2, PA, and PB1. Among the detected mutations, PB1-K577E was a novel mutation that had not been previously reported to involve mammalian adaptation. A recombinant H9N2 virus bearing only the PB1-K577E mutation showed enhanced pathogenicity in mice, with increased virus titers in nasal turbinates compared to that in mice infected with the wild-type virus. In addition, the PB1-K577E mutation increased virus polymerase activity in human cell culture at a lower temperature. These data suggest that the PB1-K577E mutation is a novel pathogenicity determinant of H9N2 virus in mice and could be a signature for mammalian adaptation.

scholarly journals Glucose Oxidation by Normal and Virus-Infected Mice

1956 ◽  
Vol 184 (2) ◽  
pp. 356-358 ◽  
Author(s):  
Benjamin V. Siegel ◽  
Ann M. Hughes
Keyword(s):  
Glucose Metabolism ◽  
Glucose Oxidation ◽  
Apparent Effect ◽  
Diseased Animal ◽  
Poliomyelitis Virus ◽  
Viral Multiplication

The oxidation of uniformly labeled C14-glucose by normal mice and mice infected with strain MEF1 poliomyelitis virus was determined in an apparatus designed to measure respiratory radioactivity excretion. The respiration of normal and virus-infected mice was found to be essentially the same over a 10-day period of infection, although the production of virus in the diseased animal during this time was considerable. It is concluded that the rate and extent of viral multiplication in poliomyelitis is without apparent effect on the rate and extent of glucose metabolism by the infected intact host.

scholarly journals Promiscuous Pathogenicity Islands and Phylogeny of Pathogenic Streptomyces spp.

2016 ◽  
Vol 29 (8) ◽  
pp. 640-650 ◽  
Author(s):  
Yucheng Zhang ◽  
Dawn R. D. Bignell ◽  
Ran Zuo ◽  
Qiurong Fan ◽  
Jose C. Huguet-Tapia ◽  
...  
Keyword(s):  
Potato Scab ◽  
Pathogenic Species ◽  
Genome Sequences ◽  
Streptomyces Species ◽  
Streptomyces Sp ◽  
Streptomyces Spp ◽  
Streptomyces Turgidiscabies ◽  
Streptomyces Diastatochromogenes ◽  
Pathogenicity Determinant

Approximately 10 Streptomyces species cause disease on underground plant structures. The most economically important of these is potato scab, and the most studied of these pathogens is Streptomyces scabiei (syn. S. scabies). The main pathogenicity determinant of scab-causing Streptomyces species is a nitrated diketopiperazine, known as thaxtomin A (ThxA). In the pathogenic species Streptomyces turgidiscabies, ThxA biosynthetic genes reside on a mobile pathogenicity island (PAI). However, the mobilization of PAIs in other Streptomyces species remains uncharacterized. Here, we investigated the mobilization of the PAI of S. scabiei 87-22. Based on whole genome sequences, we inferred the evolutionary relationships of pathogenic Streptomyces species and discovered that Streptomyces sp. strain 96-12, a novel pathogenic species isolated from potatoes in Egypt, was phylogenetically grouped with nonpathogenic species rather than with known pathogenic species. We also found that Streptomyces sp. strain 96-12 contains a PAI that is almost identical to the PAI in S. scabiei 87-22, despite significant differences in their genome sequences. This suggested direct or indirect in vivo mobilization of the PAI between S. scabiei and nonpathogenic Streptomyces species. To test whether the S. scabiei 87-22 PAI could, indeed, be mobilized, S. scabiei 87-22 deletion mutants containing antibiotic resistance markers in the PAI were mated with Streptomyces diastatochromogenes, a nonpathogenic species. The PAI of S. scabiei was site-specifically inserted into the aviX1 gene of S. diastatochromogenes and conferred pathogenicity in radish seedling assays. Our results demonstrated that S. scabiei, the earliest described Streptomyces pathogen, could be the source of a PAI responsible for the emergence of novel pathogenic species.

scholarly journals The Consensus N-Myristoylation Motif of a Geminivirus AC4 Protein Is Required for Membrane Binding and Pathogenicity

2007 ◽  
Vol 20 (4) ◽  
pp. 380-391 ◽  
Author(s):  
Vincent N. Fondong ◽  
R. V. Chowda Reddy ◽  
Cheng Lu ◽  
Bertrand Hankoua ◽  
Christian Felton ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Protein ◽  
Nicotiana Benthamiana ◽  
Rna Silencing ◽  
Membrane Binding ◽  
Confocal Imaging ◽  
East African ◽  
Intrinsic Signals ◽  
Pathogenicity Determinant ◽  
Silencing Suppression

Some geminiviruses encode a small protein, AC4, whose role in pathogenesis has only recently attracted attention. A few studies have shown that this protein is involved in pathogenesis and suppresses RNA silencing. Here, using Nicotiana benthamiana, we show that East African cassava mosaic Cameroon virus (EACMCV) AC4 is a pathogenicity determinant and that it suppresses the systemic phase of RNA silencing. Furthermore, confocal imaging analyses show that it binds preferentially to the plasma membrane as well as to cytosolic membranes including the perinucleus but is excluded from the nucleus. A computational examination of the AC4 protein encoded by the EACMCV, a bipartite geminivirus, shows that it encodes a consensus N-myristoylation motif and is likely posttranslationally myristoylated and palmitoylated. Replacement of Gly-2 and Cys-3 (sites of posttranslational attachment of myristic and palmatic acids, respectively) with alanine affected AC4 membrane binding and pathogenesis. Furthermore, replacement of Ile-5, a nonessential myristoylation residue, with alanine did not affect AC4 function. Together, these data indicate that EACMCV AC4 is likely dually acylated at Gly-2 and Cys-3 and that these modifications are intrinsic signals for membrane targeting and pathogenesis. This is the first report of a membrane protein to be involved in pathogenesis and RNA silencing suppression.

Anti-P30-52 Monoclonal Antibody Cross-Reacted to Env V3 and Inhibited the Viral Multiplication of HIV-1-Infected MT-4 Cells

Hybridoma ◽  
1999 ◽  
Vol 18 (2) ◽  
pp. 139-147 ◽  
Author(s):  
AKEMI OTA ◽  
ANALISA N. BAUTISTA ◽  
MUNAR LAL YADAV ◽  
SIGEHARU UEDA
Keyword(s):  
Monoclonal Antibody ◽  
Viral Multiplication ◽  
Hiv 1

scholarly journals Pathogenicity of Pepper mild mottle virus Is Controlled by the RNA Silencing Suppression Activity of Its Replication Protein but Not the Viral Accumulation

2007 ◽  
Vol 97 (4) ◽  
pp. 412-420 ◽  
Author(s):  
Shinya Tsuda ◽  
Kenji Kubota ◽  
Ayami Kanda ◽  
Takehiro Ohki ◽  
Tetsuo Meshi
Keyword(s):  
Amino Acid ◽  
Replication Protein ◽  
Mottle Virus ◽  
Wild Type Virus ◽  
Base Substitution ◽  
Pepper Mild Mottle Virus ◽  
Posttranscriptional Gene Silencing ◽  
Virus Accumulation ◽  
Pathogenicity Determinant ◽  
The Relationship

Pepper mild mottle virus (PMMoV) infects pepper plants, causing mosaic symptoms on the upper developing leaves. We investigated the relationship between a virus pathogenicity determinant domain and the appearance of mosaic symptoms. Genetically modified PMMoV mutants were constructed, which had a base substitution in the 130K replication protein gene causing an amino acid change or a truncation of the 3′ terminal pseudoknot structure. Only one substitution mutant (at amino acid residue 349) failed to cause symptoms, although its accumulation was relatively high. Conversely, the pseudoknot mutants showed the lower accumulation, but they still caused mosaic symptoms as severe as the wild-type virus. Therefore, the level of virus accumulation in a plant does not necessarily correlate with the development of mosaic symptoms. The activity to suppress posttranscriptional gene silencing (PTGS) was impaired in the asymptomatic mutant. Consequently, pathogenicity causing mosaic symptoms should be controlled by combat between host PTGS and its suppression by the 130K replication protein rather than virus accumulation.

scholarly journals A New Strain of Streptomyces Causing Common Scab in Potato

Plant Disease ◽  
2007 ◽  
Vol 91 (4) ◽  
pp. 352-359 ◽  
Author(s):  
Leslie A. Wanner
Keyword(s):  
16S Rdna ◽  
Horizontal Transfer ◽  
Common Scab ◽  
The United States ◽  
Streptomyces Species ◽  
Genus Streptomyces ◽  
16S Rdna Sequence ◽  
Genes Encoding ◽  
Pathogenicity Determinant ◽  
Serious Disease

Common scab is a serious disease of potatoes (Solanum tuberosum) and other root and tuber crops, affecting the quality and market value of these crops. The disease is caused by gram-positive soil bacteria in the genus Streptomyces. A new common scab-causing streptomycete was isolated from scabby potatoes originating in southeastern Idaho. Research has supported a model of horizontal transfer of pathogenicity determinants among streptomycetes, and the new strain has hallmarks of the recently characterized Streptomyces pathogenicity island (PAI); it has genes encoding the synthetase for the pathogenicity determinant thaxtomin and for a second pathogenicity factor, tomatinase, although it lacks a third gene characteristic of the Streptomyces PAI, the nec1 gene. The new strain has a unique 16s rDNA gene sequence closely related to those of other pathogenic Streptomyces species. This 16s rDNA sequence was also found in isolates lacking a PAI, suggesting that the new pathogenic strain arose by horizontal transfer of a PAI into a saprophytic streptomycete. Isolates of the new strain are pathogenic on radish and potato, and are more virulent than the S. scabies type strain. In addition to scab lesions on potato tubers, lesions were also seen on underground stems and stolons. This new strain represents additional complexity in the pathogenic strains causing plant disease in the United States.

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