Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017160 (gastroenteritis)
 11,398 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Norovirus is a major cause of diarrheal disease with epidemic, outbreak or sporadic patterns in humans of all ages worldwide. This study aimed to determine the genotypic characteristics of noroviruses from infants and children in Beijing. Stool samples (n=1128) were collected from patients with symptoms of acute gastroenteritis in the past 3 years from 2010 to 2012. The norovirus positivity rate was 16.1% (182/1128) by using RT-PCR, including 122 with primer set covering polymerase region, 177 with primer set covering capsid region, and 117 with both polymerase and capsid regions. By sequence analysis for capsid genes, all the noroviruses identified were belonging to genogroup II (GII). Among these positive samples, GII.4 (61.0%) was the most common genotype detected, followed by GII.3 (35.0%). The new variant GII.4 Sydney_2012 strains emerged in this study in September and became the predominant genotype later. Those 117 from 182 RT-PCR positive samplers were able to be genotyped based on the sequences of both polymerase and capsid genes. The result was interesting that 59 out of these 117 positive specimens (50.4%) had mismatched genotypes between polymerase and capsid genes, including 7 suspected recombinants patterns. Among them, GII.P12/GII.3 was the most common combination which accounts for 54.2% (32/59), followed by GII.Pe/GII.4 Sydney_2012 which was 23.7% (14/59). Two novel recombinants, GII.P22/GII.5 and GII.21/GII.3 were first detected in this study. In summary, this study provides a detailed description based on laboratory data of the genetic diversity of norovirus in young children with acute gastroenteritis in Beijing. Moreover the data revealed that in the evolution of norovirus, new variant and novel recombination emerged frequently.
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PMID:Prevalence and genetic diversity of noroviruses in outpatient pediatric clinics in Beijing, China 2010-2012. 2521 87

Norovirus (NoV) is responsible for outbreaks and sporadic cases of nonbacterial acute gastroenteritis in humans worldwide. The virus consists of small round particles containing a single-stranded RNA genome that is divided into three Open Reading Frames. NoV evolves via mechanisms of antigenic drift and recombination, which lead to the emergence of new strains that are capable of causing global epidemics. Recombination usually occurs in the ORF1/ORF2 overlapping region and generates strains with different genotypes in the polymerase and capsid region. The primary objective of this study was to analyze recombination in positive-NoV samples. Specimens were collected during 2011, 2012 and 2014, from children under two years of age presenting gastrointestinal symptoms such as vomiting and diarrhea. The partial polymerase (B region), capsid (D region) genes and the ORF1-ORF2 overlap regions were sequenced in each sample. The recombinant analyses were performed in the Simplot software v.3.5.1 and RDP4 Beta v. 4.6 program. These analyses showed that GII.Pg/GII.1, GII.P7/GII.6, and GII.P22/GII.5 were recombinant strains. To our knowledge, this is the first time that the GII.P22/GII.5 and GII.Pg/GII.1 strains were described in South America and the GII.P7/GII.6 was detected in Northern of Brazil.
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PMID:Analysis of uncommon norovirus recombinants from Manaus, Amazon region, Brazil: GII.P22/GII.5, GII.P7/GII.6 and GII.Pg/GII.1. 2686 19

The genotype II.4 (GII.4) variants of human noroviruses (HuNVs) are recognized as the major agent of global gastroenteritis outbreaks. Due to the lack of an efficient cell culture system for HuNV propagation, the exact roles of HuNV-encoded nonstructural proteins (including Nterm, NTPase, P22, VPg, Pro, and RdRp) in viral replication or pathogenesis have not yet been fully understood. Here, we report the molecular characterization of the GII.4 HuNV-encoded NTPase (designated GII-NTPase). Results from our studies showed that GII-NTPase forms vesicular or nonvesicular textures in the cell cytoplasm, and the nonvesicular fraction of GII-NTPase significantly localizes to the endoplasmic reticulum (ER) or mitochondria. Deletion analysis revealed that the N-terminal 179-amino-acid (aa) region of GII-NTPase is required for vesicle formation and for ER colocalization, whereas the C-terminal region is involved in mitochondrial colocalization. In particular, two mitochondrion-targeting domains were identified in the C-terminal region of GII-NTPase which perfectly colocalized with mitochondria when the N-terminal region of GII-NTPase was deleted. However, the corresponding C-terminal portions of NTPase derived from the GI HuNV did not show mitochondrial colocalization. We also found that GII-NTPase physically interacts with itself as well as with Nterm and P22, but not VPg, Pro, and RdRp, in cells. The Nterm- and P22-interacting region was mapped to the N-terminal 179-aa region of GII-NTPase, whereas the self-assembly of GII-NTPase could be achieved via a head-to-head, tail-to-tail, or head-to-tail configuration. More importantly, we demonstrate that GII-NTPase possesses a proapoptotic activity, which can be further enhanced by coexpression with Nterm or P22.IMPORTANCE Despite the importance of human norovirus GII.4 variants in global gastroenteritis outbreaks, the basic biological functions of the viral nonstructural proteins in cells remain rarely investigated. In this report, we focus our studies on characteristics of the GII.4 norovirus-encoded NTPase (GII-NTPase). We unexpectedly find that GII-NTPase can perfectly colocalize with mitochondria after its N-terminal region is deleted. However, such a phenomenon is not observed for NTPase encoded by a GI strain. We further reveal that the N-terminal 179-aa region of GII-NTPase is sufficient to mediate (i) vesicle formation, (ii) ER colocalization, (iii) the interaction with two other nonstructural proteins, including Nterm and P22, (iv) the formation of homodimers or homo-oligomers, and (v) the induction of cell apoptosis. Taken together, our findings emphasize that the virus-encoded NTPase must have multiple activities during viral replication or pathogenesis; however, these activities may vary somewhat among different genogroups.
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PMID:Subcellular Localization and Functional Characterization of GII.4 Norovirus-Encoded NTPase. 2921 38