ABSTRACT Following infection with most reovirus strains, viral protein synthesis is robust, even when cellular translation inhibited. To gain further insight into pathways that regulate in reovirus-infected cells, we performed a comparative microarray analysis of gene expression following two strains inhibit host (clone 8 and clone 87) one strain does not (Dearing). Infection 87 significantly increased the genes characteristic stress responses, including integrated response. these same...

By atomic absorption analysis, we determined that the reovirus outer capsid protein sigma 3, which binds double-stranded RNA (dsRNA), is a zinc metalloprotein. Using Northwestern blots and novel blotting technique, localized zinc- dsRNA-binding activities of 3 to distinct V8 protease-generated fragments. Zinc-binding activity was contained within an amino-terminal fragment transcription factor IIIA-like zinc-binding sequence, associated with carboxy-terminal fragment. these techniques, new...

The structural protein mu 1 of mammalian reoviruses was noted to have a potential N-myristoylation sequence at the amino terminus its deduced acid sequence. Virions labeled with [3H]myristic were used demonstrate that is modified by an amide-linked myristoyl group. A myristoylated peptide having relative molecular weight (Mr) approximately 4,000 also shown be component virions and concluded represent 4.2-kDa amino-terminal fragment which generated same proteolytic cleavage yields...

ABSTRACT Entry of reovirus virions has been well studied in several tissue culture systems. After attachment to junctional adhesion molecule A (JAM-A), undergo clathrin-mediated endocytosis followed by proteolytic disassembly the capsid and penetration cytoplasm. However, during vivo infection intestinal tract, likely tumor microenvironment, proteolysis (uncoating) is initiated extracellularly. We used multiple approaches determine if uncoated particles, called intermediate subviral...

Developing critical-thinking and scientific reasoning skills are core learning objectives of science education, but little empirical evidence exists regarding the interrelationships between these constructs. Writing effectively fosters students' development constructs, it offers a unique window into studying how they relate. In this study undergraduate thesis writing in biology at two universities, we examine exhibited (assessed using Biology Thesis Assessment Protocol) relates to general...

ABSTRACT Reovirus outer-capsid proteins μ1, ς3, and ς1 are thought to be assembled onto nascent core-like particles within infected cells, leading the production of progeny virions. Consistent with this model, we report in vitro assembly baculovirus-expressed μ1 ς3 purified cores that lack ς1. The resulting (recoated cores, or r-cores) closely resembled native virions protein composition (except for lacking cell attachment ς1), buoyant density, particle morphology by scanning cryoelectron...

We have characterized a simple method that uses 65ZnCl2 to detect zinc-binding proteins been immobilized on nitrocellulose. Conditions identified permit the detection of as little 1 microgram some proteins. The specificity binding is indicated by ability other divalent metal ions compete with 65Zn(II) in this assay. used technique provide evidence nucleic acid-binding gag protein retroviruses also binds zinc. This can be applied biological mixtures and may proteolytic mapping studies...

See page 1406Mammalian ortheoreoviruses are currently being investigated as novel cancer therapeutics, but the cellular mechanisms that regulate susceptibility to reovirus oncolysis remain poorly understood. In this study, we present evidence virion disassembly is a key determinant of oncolysis. To penetrate cell membranes and initiate infection, outermost capsid proteins must be proteolyzed generate disassembled particle called an infectious subviral (ISVP). fibroblasts, process mediated by...

ABSTRACT We previously hypothesized that efficient translation of influenza virus mRNA requires the recruitment P58 IPK , cellular inhibitor PKR, an interferon-induced kinase targets eukaryotic initiation factor eIF2α. also inhibits PERK, eIF2α is localized in endoplasmic reticulum (ER) and induced during ER stress. The ability to interact with inhibit multiple kinases suggests it a critical regulator both viral translation. In this study, we sought definitively define role infection...

Cellular translation is inhibited following infection with most strains of reovirus, but the mechanisms responsible for this phenomenon remain to be elucidated. The extent host shutoff varies in a strain-dependent manner; majority leads strong shutoff, while strain Dearing results minimal inhibition cellular translation. A genetic study reassortant viruses and subsequent biochemical analyses led hypothesis that interferon-induced, double-stranded RNA-activated protein kinase, PKR,...

The S2 gene nucleotide sequences of prototype strains the three reovirus serotypes were determined to gain insight into structure and function translation product, virion core protein sigma 2. type 1 Lang, 2 Jones, 3 Dearing are 1,331 nucleotides in length contain a single large open reading frame that could encode 418 amino acids, corresponding deduced acid these very conserved, being identical at 94% sequence positions. Predictions secondary hydrophobicity suggest has two-domain structure....

ABSTRACT Virion uncoating is a critical step in the life cycle of mammalian orthoreoviruses. In cell culture, and probably extraintestinal tissues vivo, reovirus virions undergo partial proteolysis within endosomal or/or lysosomal compartments. This process converts virion into form referred to as an intermediate subvirion particle (ISVP). natural enteric infections, proteolytic takes place extracellularly intestinal lumen. The resultant proteolyzed particles, unlike intact virions, have...

In murine fibroblasts, efficient proteolysis of reovirus outer capsid protein sigma3 during cell entry by virions requires the acid-dependent lysosomal cysteine protease cathepsin L. The importance L for infection other types is unknown. Here we report that acid-independent S mediates processing in macrophage-like P388D cells. cells supported strain Lang, but not c43. Genetic studies revealed this difference determined S4, viral gene segment encodes sigma3. c43-derived subvirion particles...

By atomic absorption analysis, we determined that the reovirus outer capsid protein sigma 3, which binds double-stranded RNA (dsRNA), is a zinc metalloprotein. Using Northwestern blots and novel blotting technique, localized zinc- dsRNA-binding activities of 3 to distinct V8 protease-generated fragments. Zinc-binding activity was contained within an amino-terminal fragment transcription factor IIIA-like zinc-binding sequence, associated with carboxy-terminal fragment. these techniques, new...

ABSTRACT Virion uncoating is an essential early event in reovirus infection. In natural enteric infections, rapid proteolytic of virions mediated by pancreatic serine proteases. The proteases that promote disassembly and cell entry the respiratory tract remain unknown. this report, we show endogenous inflammatory can infection vitro preexisting inflammation augments vivo murine tract.

ABSTRACT Structure-function studies with mammalian reoviruses have been limited by the lack of a reverse-genetic system for engineering mutations into viral genome. To circumvent this limitation in partial way major outer-capsid protein ς3, we obtained vitro assembly large numbers virion-like particles binding baculovirus-expressed ς3 to infectious subvirion (ISVPs) that ς3. A level approaching 100% native virions was routinely achieved. The coat these recoated ISVPs (rcISVPs) appeared very...

ABSTRACT Reovirus nonstructural protein ςNS interacts with reovirus plus-strand RNAs in infected cells, but little is known about the nature of those interactions or their roles viral replication. In this study, a recombinant form was analyzed for vitro binding to nucleic acids using gel mobility shift assays. Multiple units bound single-stranded RNA molecules positive cooperativity and each unit covering 25 nucleotides at saturation. The did not bind preferentially over nonreovirus...

ABSTRACT Entry of mammalian reovirus virions into target cells requires proteolytic processing surface protein σ3. In the virion, σ3 mostly covers membrane-penetration μ1, appearing to keep it in an inactive form and prevent from interacting with cellular membrane until proper time infection. The molecular mechanism by which maintains μ1 this state structural changes that accompany activation, however, are not well understood. study we characterized early steps determined their effects on...

ABSTRACT Many viruses invade mucosal surfaces to establish infection in the host. Some are restricted surfaces, whereas others disseminate sites of secondary replication. Studies strain-specific differences reovirus and systemic dissemination have enhanced an understanding viral determinants molecular mechanisms that regulate pathogenesis. After peroral inoculation, strain type 1 Lang replicates high titers intestine spreads systemically, 3 Dearing (T3D) does not. These segregate with S1...

Association of the reovirus proteins sigma 3 and mu 1 influences viral entry, initiation outer capsid assembly, modulation effect on cellular translation. In this study, we have addressed whether structural changes occur in as a result its interaction with 1. Using differences protease sensitivity to detect conformationally distinct forms 3, showed that association caused conformational change converted it from protease-resistant protease-sensitive structure occurred posttranslationally. The...

Various personal dimensions of students-particularly motivation, self-efficacy beliefs, and epistemic beliefs-can change in response to teaching, affect student learning, be conceptualized as learning dispositions. We propose that these dispositions serve outcomes their own right; patterns interrelationships among specific are likely; differing constellations (or disposition profiles) may have meaningful implications for instructional practices. In this observational study, we examine...