Structure and Expression of Large (+)RNA Genomes of Viruses of Higher Eukaryotes.

Viral positive-sense RNA genomes evolve rapidly due to the high mutation rates during replication and RNA recombination, which allowing the viruses to acquire and modify genes for their adaptation. The size of RNA genome is limited by several factors, including low fidelity of RNA polymerases and packaging constraints. However, the 12-kb size limit is exceeded in the two groups of eukaryotic (+)RNA viruses - animal nidoviruses and plant closteroviruses.

Molecular Alliance of Lymantria dispar Multiple Nucleopolyhedrovirus and a Short Unmodified Antisense Oligonucleotide of Its Anti-Apoptotic IAP-3 Gene: A Novel Approach for Gypsy Moth Control.

Baculovirus IAP (inhibitor-of-apoptosis) genes originated by capture of host genes. Unmodified short antisense DNA oligonucleotides (oligoDNAs) from baculovirus IAP genes can down-regulate specific gene expression profiles in both baculovirus-free and baculovirus-infected insects. In this study, gypsy moth () larvae infected with multiple nucleopolyhedrovirus (LdMNPV), and LdMNPV-free larvae, were treated with oligoDNA antisense to the RING (really interesting new gene) domain of the LdMNPV gene.

Structural evolution of the 4/1 genes and proteins in non-vascular and lower vascular plants.

The 4/1 protein of unknown function is encoded by a single-copy gene in most higher plants. The 4/1 protein of Nicotiana tabacum (Nt-4/1 protein) has been shown to be alpha-helical and predominantly expressed in conductive tissues. Here, we report the analysis of 4/1 genes and the encoded proteins of lower land plants.

Beet yellows virus replicase and replicative compartments: parallels with other RNA viruses.

In eukaryotic virus systems, infection leads to induction of membranous compartments in which replication occurs. Virus-encoded subunits of the replication complex mediate its interaction with membranes. As replication platforms, RNA viruses use the cytoplasmic surfaces of different membrane compartments, e.

Completion of the mapping of transcription start sites for the five-gene block subgenomic RNAs of Beet yellows Closterovirus and identification of putative subgenomic promoters.

In the positive-sense RNA genome of Beet yellows Closterovirus (BYV), the 3'-terminal open reading frames (ORFs) 2-8 are expressed as a nested set of subgenomic (sg) RNAs. ORFs 2-6, coding for the structural and movement proteins, form a 'five-gene block' conserved in closteroviruses. We mapped the 5'-end of the ORF 4 sgRNA, which encodes the p64 protein, at adenosine-11169 in the BYV genome.

Processing and subcellular localization of the leader papain-like proteinase of Beet yellows closterovirus.

ORF 1a of Beet yellows closterovirus (BYV) encodes the domains of the papain-like proteinase (PCP), methyltransferase (MT) and RNA helicase. BYV cDNA inserts encoding the PCP-MT region were cloned in pGEX vectors next to the glutathione S-transferase gene (GST). In a 'double tag' construct, the GST-PCP-MT cDNA was flanked by the 3'-terminal six histidine triplets.

Ultrastructural localization and epitope mapping of the methyltransferase-like and helicase-like proteins of Beet yellows virus.

Monoclonal antibodies (MAbs) specific to the methyltransferase (MT) and helicase (HEL) domains of the closterovirus Beet yellows virus (BYV) were used for immunogold labelling of ultrathin sections of virus-infected Tetragonia expansa plants. MAbs 4A2 and 4A5 from the MT panel, and 1C4 from the HEL panel, specifically labelled distinct closterovirus-induced membranous structures, the 'BYV-type vesicles', thus suggesting that the closterovirus MT-like and HEL-like proteins co-localize in these structures. Probing of the MT and HEL MAbs with synthetic octapeptides spanning the sequences of the recombinant MT and HEL fragments that had been used as immunogens showed that 4A5 and 4A2 recognized a single epitope, SRLLENET (aa 686-692 in the BYV 1a protein), and 1C4 reacted with the DDPF epitope (aa 2493-2496).