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)

The polypeptides of purified preparations of the coronavirus responsible for transmissible gastroenteritis of pigs have beem examined by polyacrylamide gel electrophoresis. Four major polypeptides, VPI (mol. wt. 200000), VP2 (50 000), VP3 (30000) and VP4 (28500) and two minor polypeptides, VPIa (105000) and VPIb (80500) have been reproducibly demonstrated in the virion, of which VPI, VP3 and VP4 contain carbohydrate. Treatment of the virion with the proteolytic enzyme bromelain removes the surface projections and VPI, thus identifying this glycopolypeptide as the major structural component of the projection.
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PMID:The polypeptide structure of transmissible gastroenteritis virus. 17 35

Exposure of purified transmissible gastroenteritis virus, a porcine coronavirus, to non-ionic detergents resulted in the removal of the surface projections and greater than 98% of the virus lipid. Virus RNA was associated with a subviral particle which had a sedimentation coefficient of 650S, compared with 495S for the intact virion, and which banded in Cs2SO4 gradients at 1-295 g/ml. Negatively stained preparations of subviral particles were shown by electron microscopy to contain spherical particles of 60 to 70 nm diam., similar in appearance to those derived from oncornaviruses. Polyacrylamide gel electrophoresis of the polypeptides from isolated subviral particles showed that these structures contained three of the four major virus structural proteins, the arginine-rich polypeptide VP2 and the two membrane glycopolypeptides VP2 and 4. The detergent-liberated surface projections, composed of a single species of sulphated glycopolypeptide, VPI, were isolated by rate-zonal centrifugation through sucrose gradients followed by precipitation with ammonium sulphate in the presence of bovine serum albumin.
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PMID:Isolation of subviral components from transmissible gastroenteritis virus. 19 Mar 41

Enzymic and biophysical studies with purified infantile gastroenteritis virus (IGV) nucleic acid indicated that the virion contained a double-stranded RNA genome of approx. 14 x 10(6) daltons which could be separated by gel electrophoresis into eight bands of RNA which were comprised of 15 RNA species. Two major virus proteins, VP2 (mol. wt. = 135,000) and VP8 (mol. wt. = 40,000), which composed about 85% of the total virion protein, were detected in IGV particles by polyacrylamide gel electrophoresis. Eight additional minor proteins were also resolved.
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PMID:Biochemical characterization of infantile gastroenteritis virus (IGV). 40 93

Rotaviruses are the leading cause of severe infantile gastroenteritis worldwide. These viruses are large, complex icosahedral particles consisting of three concentric capsid layers enclosing a genome of eleven segments of double-stranded RNA (dsRNA). The amino terminus of the innermost capsid protein VP2 possesses a nonspecific single-stranded RNA and dsRNA binding activity, and the amino terminus is also essential for the incorporation of the polymerase enzyme VP1 and guanylyltransferase VP3 into the core of the virion. Biochemical and structural studies have suggested that VP2, and especially the amino terminus, appears to act as a scaffold for proper assembly of the components of the viral core. To locate the amino terminus of VP2 within the core, we have used electron cryomicroscopy and image reconstruction to determine the three-dimensional structures of recombinant virus-like particles that contain either full-length or amino-terminal-deleted forms of VP2 coexpressed with the intermediate capsid protein VP6. A comparison of these structures indicates two significant changes along the inner surface of VP2 in the structure lacking the amino terminus: a loss of mass adjacent to the fivefold axes and a redistribution of mass along the fivefold axes. Examination of the VP2 layer suggests that the proteins are arranged as dimers of 120 quasi-equivalent molecules, with each dimer extending between neighboring fivefold axes. Our results indicate that the amino termini of both quasi-equivalent VP2 molecules are located near the icosahedral vertices.
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PMID:Three-dimensional structural analysis of recombinant rotavirus-like particles with intact and amino-terminal-deleted VP2: implications for the architecture of the VP2 capsid layer. 931 13

Rotavirus-specific IgA has been correlated with immune protection against rotavirus reinfection and symptomatic disease. Systemic and mucosal antibody responses were determined by an enzyme-linked immunosorbent assay in 11 infants with severe rotavirus gastroenteritis. Geometric mean titers of antirotavirus serum IgG and IgA antibodies were significantly higher during the convalescence of the disease (P < 0.001 vs. acute-phase titers). Rotavirus-specific fecal sIgA antibodies increased 4 times during the convalescence in 9 (81.8%) children (P < 0.001). The serum IgG and IgA antibody and fecal sIgA antibody responses to individual rotavirus polypeptides were characterized by radioimmunoprecipitation assay (RIPA) using Staphylococcus aureus protein A and the lectin jacalin to precipitate IgG- and IgA-immune complexes, respectively. The main IgG response was directed toward the structural viral proteins VP2, VP4, and VP6 and toward the nonstructural protein NSP2. Serum IgA reactivity was detected by RIPA in all serum samples, with major responses to VP2, VP6, and NSP2. Interestingly, fecal sIgA in convalescent samples reacted strongly toward NSP2 and VP6. These data reinforce the antigenic importance of rotaviral proteins other than VP4 and VP7, such as VP2, VP6, and NSP2, as main targets in the immune response to rotavirus.
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PMID:Viral proteins VP2, VP6, and NSP2 are strongly precipitated by serum and fecal antibodies from children with rotavirus symptomatic infection. 970 Jun 34

Between June 4th and June 20th 1996 rotavirus, adenovirus, and astrovirus (HAstrV) were investigated in fecal samples from 27 children under three years old with acute diarrhea, attending the Bertha Lutz day care center, in Rio de Janeiro. All fecal samples were analyzed by polyacrylamide gel electrophoresis (PAGE), reverse transcriptase polymerase chain reaction (RT-PCR), enzyme immunoassays (EIA), and electron microscopy (EM). Nine of them (33%) showed positive results for HAstrV by at least one of the employed methodologies. Eight were positive by RT-PCR and EIA, and six by EM. All positive samples were inoculated onto HT-29 (human colon adenocarcinoma) cultured cells for HAstrV isolation and seven were positive after three passages. The sequencing analysis of eight RT-PCR products (449 bp) from gene that codifies VP2 protein, showed a total nucleotide identity among them and 98% with HAstrV-1 (strain Oxford type 1). This is the first report of a gastroenteritis outbreak associated with HAstrv-1 in a day care center in Rio de Janeiro and it reinforces the importance of this virus in association with infantile acute gastroenteritis.
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PMID:An outbreak of gastroenteritis associated with astrovirus serotype 1 in a day care center, in Rio de Janeiro, Brazil. 1178 24

Snow Mountain virus (SMV) belongs to the Norovirus genus of the Caliciviridae family. SMV is a genogroup II (GII) reference strain of human enteric caliciviruses associated with epidemic gastroenteritis. In this study, the positive sense RNA genome sequence of SMV was determined to be 7,537 nucleotides in length excluding the 3' polyadenylated tract. The genome is organized into three open reading frames typical of caliciviruses in the Norovirus genus. Pairwise sequence alignments showed SMV ORF1 is highly conserved with other genogroup II noroviruses, and most closely related to GII strains Melksham and Hawaii virus. In addition, comparative sequence analyses indicated that SMV is likely a recombinant norovirus. VP1/VP2 proteins self-assembled into virus-like particles (VLPs) when expressed in insect cells by a recombinant baculovirus. Characterization of one clone that expressed VP1, but failed to assemble into VLPs, identified histidine residue 91 as important for particle assembly under standard conditions of expression.
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PMID:Snow Mountain virus genome sequence and virus-like particle assembly. 1268 Jun 95

Norwalk virus (NV) is the prototype strain of a group of noncultivable human caliciviruses responsible for epidemic outbreaks of acute gastroenteritis. The capsid protein VP1 is synthesized from a subgenomic RNA that contains two open reading frames (ORFs), ORF2 and ORF3, and the 3' untranslated region (UTR). ORF2 and ORF3 code for the capsid protein (VP1) and a small structural basic protein (VP2), respectively. We discovered that the yields of virus-like particles (VLPs) composed of VP1 are significantly reduced when this protein is expressed from ORF2 alone. To determine how the 3' terminus of the NV subgenomic RNA regulates VP1 expression, we compared VP1 expression levels by using recombinant baculovirus constructs containing different 3' elements. High VP1 levels were detected by using a recombinant baculovirus that contained ORF2, ORF3, and the 3'UTR (ORF2+3+3'UTR). In contrast, expression of VP1 from constructs that lacked the 3'UTR (ORF2+3), ORF3 (ORF2+3'UTR), or both (ORF2 alone) was highly reduced. Elimination of VP2 synthesis from the subgenomic RNA by mutation resulted in VP1 levels similar to those obtained with the ORF2 construct alone, suggesting a cis role for VP2 in upregulation of VP1 expression levels. Comparisons of the kinetics of RNA and capsid protein expression levels by using constructs with or without ORF3 or the 3'UTR revealed that the 3'UTR increased the levels of VP1 RNA, whereas the presence of VP2 resulted in increased levels of VP1. Furthermore, VP2 increased VP1 stability and protected VP1 from disassembly and protease degradation. The increase in VP1 expression levels caused by the presence of VP2 in cis was also observed in mammalian cells.
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PMID:The 3' end of Norwalk virus mRNA contains determinants that regulate the expression and stability of the viral capsid protein VP1: a novel function for the VP2 protein. 1455 46

Rotaviruses, members of family Reoviridae, are a major cause of acute gastroenteritis of infants and young children. The rotavirus genome consists of 11 segments of double-stranded (ds)RNA and the virion is an icosahedron composed of multiple layers of protein. The virion core is formed by a layer of VP2 and contains multiple copies of the RNA-dependent RNA polymerase VP1 and the mRNA-capping enzyme VP3. Double-layered particles (DLPs), representing cores surrounded by a layer of VP6, direct the synthesis of viral mRNAs. Rotavirus core- and DLP-like replication intermediates (RIs) catalyze the synthesis of dsRNA from viral template mRNAs coincidentally with the packaging of the mRNAs into the pre-capsid structures of RIs. In addition to structural proteins, the nonstructural proteins NSP2 and NSP5 are components of RIs with replicase activity. NSP2 self assembles into octameric structures that have affinity for ssRNA and NTPase and helix-destabilizing activites. Its interaction with nucleotides induces a conformational shift in the octamer to a more condensed form. Phosphate residues generated by the NTPase activity are believed to be transferred from NSP2 to NSP5, leading to the hyperphosphorylation of the latter protein. It is suspected that the transfer of the phosphate group to NSP5 allows NSP2 to return to its noncondensed state and, thus, to accept another NTP molecule. The NSP5-mediated cycling of NSP2 from condensed to noncondensed combined with its RNA binding and helix-destabilizing activities are consistent with NSP2 functioning as a molecular motor to facilitate the packaging of template mRNAs into the pre-capsid structures of RIs. Similarities with the bluetongue virus protein NS2 and the reovirus proteins sigmaNS and micro2 suggest that they may be functional homologs of rotavirus NSP2 and NSP5.
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PMID:Nonstructural proteins involved in genome packaging and replication of rotaviruses and other members of the Reoviridae. 1501 Feb 17

Caliciviruses are a major cause of gastroenteritis in humans and cause a wide variety of other diseases in animals. Here, the characterization of protein-protein interactions between the individual proteins of Feline calicivirus (FCV), a model system for other members of the family Caliciviridae, is reported. Using the yeast two-hybrid system combined with a number of other approaches, it is demonstrated that the p32 protein (the picornavirus 2B analogue) of FCV interacts with p39 (2C), p30 (3A) and p76 (3CD). The FCV protease/RNA polymerase (ProPol) p76 was found to form homo-oligomers, as well as to interact with VPg and ORF2, the region encoding the major capsid protein VP1. A weak interaction was also observed between p76 and the minor capsid protein encoded by ORF3 (VP2). ORF2 protein was found to interact with VPg, p76 and VP2. The potential roles of the interactions in calicivirus replication are discussed.
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PMID:Analysis of protein-protein interactions in the feline calicivirus replication complex. 1643 23


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