| paramyxovirus and reovirus infections in wild-caught mexican lizards (xenosaurus and abronia spp.). | virus isolation attempts were carried out on wild-caught xenosaurus grandis, x. platyceps, and abronia graminea from mexico. these animals were also tested for exposure to paramyxoviruses and reoviruses. pharyngeal and cloacal swabs were collected from 30 lizards, and blood was collected from 23 lizards. a cytopathogenic virus was isolated from the cloacal swab of one of the x. platyceps. the isolate was identified as a paramyxovirus on the basis of its sensitivity to chloroform, resistance to 5 ... | 2002 | 12564527 |
| reptilian reovirus: a new fusogenic orthoreovirus species. | the fusogenic subgroup of orthoreoviruses contains most of the few known examples of non-enveloped viruses capable of inducing syncytium formation. the only unclassified orthoreoviruses at the species level represent several fusogenic reptilian isolates. to clarify the relationship of reptilian reoviruses (rrv) to the existing fusogenic and nonfusogenic orthoreovirus species, we undertook a characterization of a python reovirus isolate. biochemical, biophysical, and biological analyses confirmed ... | 2004 | 14967494 |
| reptilian reovirus utilizes a small type iii protein with an external myristylated amino terminus to mediate cell-cell fusion. | reptilian reovirus is one of a limited number of nonenveloped viruses that are capable of inducing cell-cell fusion. a small, hydrophobic, basic, 125-amino-acid fusion protein encoded by the first open reading frame of a bicistronic viral mrna is responsible for this fusion activity. sequence comparisons to previously characterized reovirus fusion proteins indicated that p14 represents a new member of the fusion-associated small transmembrane (fast) protein family. topological analysis revealed ... | 2004 | 15047847 |
| myristoylation, a protruding loop, and structural plasticity are essential features of a nonenveloped virus fusion peptide motif. | members of the fusion-associated small transmembrane (fast) protein family are a distinct class of membrane fusion proteins encoded by nonenveloped fusogenic reoviruses. the 125-residue p14 fast protein of reptilian reovirus has an approximately 38-residue myristoylated n-terminal ectodomain containing a moderately apolar n-proximal region, termed the hydrophobic patch. mutagenic analysis indicated sequence-specific elements in the n-proximal portion of the p14 hydrophobic patch affected cell-ce ... | 2004 | 15448165 |
| extensive syncytium formation mediated by the reovirus fast proteins triggers apoptosis-induced membrane instability. | the fusion-associated small transmembrane (fast) proteins of the fusogenic reoviruses are the only known examples of membrane fusion proteins encoded by non-enveloped viruses. while the involvement of the fast proteins in mediating extensive syncytium formation in virus-infected and -transfected cells is well established, the nature of the fusion reaction and the role of cell-cell fusion in the virus replication cycle remain unclear. to address these issues, we analyzed the syncytial phenotype i ... | 2005 | 15956554 |
| liposome reconstitution of a minimal protein-mediated membrane fusion machine. | biological membrane fusion is dependent on protein catalysts to mediate localized restructuring of lipid bilayers. a central theme in current models of protein-mediated membrane fusion involves the sequential refolding of complex homomeric or heteromeric protein fusion machines. the structural features of a new family of fusion-associated small transmembrane (fast) proteins appear incompatible with existing models of membrane fusion protein function. while the fast proteins function to induce ef ... | 2005 | 16079913 |
| the p14 fusion-associated small transmembrane (fast) protein effects membrane fusion from a subset of membrane microdomains. | the reovirus fusion-associated small transmembrane (fast) proteins are a unique family of viral membrane fusion proteins. these nonstructural viral proteins induce efficient cell-cell rather than virus-cell membrane fusion. we analyzed the lipid environment in which the reptilian reovirus p14 fast protein resides to determine the influence of the cell membrane on the fusion activity of the fast proteins. topographical mapping of the surface of fusogenic p14-containing liposomes by atomic force m ... | 2006 | 16936325 |
| the p14 fast protein of reptilian reovirus increases vesicular stomatitis virus neuropathogenesis. | the fusogenic orthoreoviruses express nonstructural fusion-associated small transmembrane (fast) proteins that induce cell-cell fusion and syncytium formation. it has been speculated that the fast proteins may serve as virulence factors by promoting virus dissemination and increased or altered cytopathology. to directly test this hypothesis, the gene encoding the p14 fast protein of reptilian reovirus was inserted into the genome of a heterologous virus that does not naturally form syncytia, ves ... | 2009 | 18971262 |
| multifaceted sequence-dependent and -independent roles for reovirus fast protein cytoplasmic tails in fusion pore formation and syncytiogenesis. | fusogenic reoviruses utilize the fast proteins, a novel family of nonstructural viral membrane fusion proteins, to induce cell-cell fusion and syncytium formation. unlike the paradigmatic enveloped virus fusion proteins, the fast proteins position the majority of their mass within and internal to the membrane in which they reside, resulting in extended c-terminal cytoplasmic tails (cts). using tail truncations, we demonstrate that the last 8 residues of the 36-residue ct of the avian reovirus p1 ... | 2009 | 19759162 |
| a unique novel reptilian paramyxovirus, four atadenovirus types and a reovirus identified in a concurrent infection of a corn snake (pantherophis guttatus) collection in germany. | in 2009, 26 clinical samples (organs and oral/cloacal swabs) from a total of 24 corn snakes (pantherophis guttatus) from a single owner were sent to our laboratory to be tested for the presence of viruses. paramyxoviruses (pmv), adenoviruses (adv) and reoviruses were detected by rt-pcr, pcr and virus isolation methods. three snakes were infected with all three viruses at the same time, while two other snakes had a double infection (pmv and reo, adv and reo) and nine other snakes had a single inf ... | 2011 | 21316873 |
| isolation and genomic characterization of a novel orthoreovirus from a brown-eared bulbul (hypsipetes amaurotis) in japan. | five species, mammalian orthoreovirus, avian orthoreovirus (arv), nelson bay orthoreovirus (nbv), baboon orthoreovirus and reptilian orthoreovirus, have been identified in the genus orthoreovirus. their genomes each consist of 10 dsrna segments. a novel orthoreovirus was isolated from the haemorrhagic intestine of a dead brown-eared bulbul (hypsipetes amaurotis) in japan. the virus formed syncytia in caco-2 and vero cells. electron microscopy revealed non-enveloped capsids of ~70 nm diameter, wh ... | 2015 | 25740958 |
| [orthoreoviruses]. | members of the genus orthoreovirus in the family reoviridae are nonenveloped, icosahedral viruses. their genomes contain 10 segments of double-stranded rna (dsrna). the orthoreoviruses are divided into two subgroups, the fusogenic and nonfusogenic reoviruses, based on the ability of the virus to induce cell-to-cell fusion. the fusogenic subgroup consists of the avian reovirus, baboon reovirus, pteropine reovirus, and reptilian reovirus, whereas the nonfusogenic subgroup consists of the prototypi ... | 2014 | 26437841 |
| reovirus fast proteins drive pore formation and syncytiogenesis using a novel helix-loop-helix fusion-inducing lipid packing sensor. | pore formation is the most energy-demanding step during virus-induced membrane fusion, where high curvature of the fusion pore rim increases the spacing between lipid headgroups, exposing the hydrophobic interior of the membrane to water. how protein fusogens breach this thermodynamic barrier to pore formation is unclear. we identified a novel fusion-inducing lipid packing sensor (flips) in the cytosolic endodomain of the baboon reovirus p15 fusion-associated small transmembrane (fast) protein t ... | 2015 | 26061049 |
| myogenic differentiation triggers pml nuclear body loss and daxx relocalization to chromocentres. | the promyelocytic leukemia protein (pml) is expressed in most normal human tissues and forms nuclear bodies (nbs) that have roles in gene regulation and cellular processes such as dna repair, cell cycle control, and cell fate decisions. using murine c2c12 myoblasts, we demonstrate that activation of skeletal muscle differentiation results in loss of pml and pml nbs prior to myotube fusion. myotube formation was associated with marked chromatin reorganization and the relocalization of daxx from p ... | 2017 | 28358373 |
| expression of the fusogenic p14 fast protein from a replication-defective adenovirus vector does not provide a therapeutic benefit in an immunocompetent mouse model of cancer. | when injected directly into a tumor mass, adenovirus (ad) vectors only transduce cells immediately along the injection tract. expression of fusogenic proteins from the ad vector can lead to syncytium formation, which efficiently spreads the therapeutic effect. fusogenic proteins can also cause cancer cell death directly, and enhance the release of exosome-like particles containing tumor-associated antigens, which boosts the anti-tumor immune response. in this study, we have examined whether deli ... | 2016 | 27740615 |
| adenovirus-mediated expression of the p14 fusion-associated small transmembrane protein promotes cancer cell fusion and apoptosis in vitro but does not provide therapeutic efficacy in a xenograft mouse model of cancer. | adenoviruses (ads) are used in numerous preclinical and clinical studies for delivery of anti-cancer therapeutic genes. unfortunately, ad has a poor ability to distribute throughout a tumor mass after intratumoral injection, and infects cells primarily within the immediate area of the injection tract. thus, ad-encoded transgene expression is typically limited to only a small percentage of cells within the tumor. one method to increase the proportion of the tumor impacted by ad is through express ... | 2016 | 26986751 |
| a novel tribasic golgi export signal directs cargo protein interaction with activated rab11 and ap-1-dependent golgi-plasma membrane trafficking. | the reovirus fusion-associated small transmembrane (fast) proteins comprise a unique family of viral membrane fusion proteins dedicated to inducing cell-cell fusion. we recently reported that a polybasic motif (pbm) in the cytosolic tail of reptilian reovirus p14 fast protein functions as a novel tribasic golgi export signal. using coimmunoprecipitation and fluorescence resonance energy transfer (fret) assays, we now show the pbm directs interaction of p14 with gtp-rab11. overexpression of domin ... | 2016 | 26941330 |
| polybasic trafficking signal mediates golgi export, er retention or er export and retrieval based on membrane-proximity. | trafficking of integral membrane proteins between the er and golgi complex, and protein sorting and trafficking between the tgn and endosomal/lysosomal compartments or plasma membranes, are dependent on cis-acting, linear amino acid sorting signals. numerous sorting signals of this type have been identified in the cytoplasmic domains of membrane proteins, several of which rely on basic residues. a novel golgi export signal that relies on a membrane-proximal polybasic motif (pbm) was recently ide ... | 2014 | 24714640 |
| efficient reovirus- and measles virus-mediated pore expansion during syncytium formation is dependent on annexin a1 and intracellular calcium. | orthoreovirus fusion-associated small transmembrane (fast) proteins are dedicated cell-cell fusogens responsible for multinucleated syncytium formation and are virulence determinants of the fusogenic reoviruses. while numerous studies on the fast proteins and enveloped-virus fusogens have delineated steps involved in membrane fusion and pore formation, little is known about the mechanics of pore expansion needed for syncytiogenesis. we now report that rna interference (rnai) knockdown of annexin ... | 2014 | 24648446 |