We used an infectious cDNA clone of porcine reproductive and respiratory syndrome virus (PRRSV) to investigate the presence of essential replication elements in the region of the genome encoding the structural proteins. Deletion analysis showed that a stretch of 34 nucleotides (14653 to 14686) within ORF7, which encodes the nucleocapsid protein, is essential for RNA replication. Strand-specific reverse transcription-PCR analysis of viral RNA isolated from transfected BHK-21 cells revealed that this region is required for negative-strand genomic RNA synthesis. The 34-nucleotide stretch is highly conserved among PRRSV isolates and folds into a putative hairpin. A 7-base sequence within the loop of this structure was suggested to base-pair with a sequence present in the loop of a hairpin located in the 3' noncoding region, resulting in a kissing interaction. Mutational analyses confirmed that this kissing interaction is required for RNA replication.
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http://dx.doi.org/10.1128/jvi.76.3.1521-1526.2002 | DOI Listing |
Retroviruses are responsible for significant pathology in humans and animals, including the acquired immunodeficiency syndrome and a wide range of malignancies. A crucial yet poorly understood step in the replication cycle is the recognition and selection of unspliced viral RNA (USvRNA) by the retroviral Gag protein, which binds to the psi (Ψ) packaging sequence in the 5' leader, to package it as genomic RNA (gRNA) into nascent virions. It was previously thought that Gag initially bound gRNA in the cytoplasm.
View Article and Find Full Text PDFCells
December 2024
Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada.
The hemoflagellate parasite is transmitted by triatomine kissing bugs and may co-infect humans together with its Chagas disease-causing congener . Using real-time quantitative polymerase chain reaction (RT-qPCR) and antimicrobial assays, we studied () the temporal and spatial distribution of in common bed bugs, , following oral ingestion and hemocoelic injection of and () the immune responses of bed bugs induced by infections. Irrespective of infection mode, no live were present in the bed bugs' hemolymph, salivary glands, or feces.
View Article and Find Full Text PDFbioRxiv
November 2024
Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio 45221-006, United States of America.
is the causative agent of Chagas disease, a zoonotic infectious disease considered a leading cause of cardiomyopathy, disability, and premature death in the Americas. This parasite spends its life between a mammalian host and an arthropod vector, undergoing essential transitions among different developmental forms. How senses microenvironmental changes that trigger cellular responses necessary for parasite survival has remained largely unknown.
View Article and Find Full Text PDFInsect Biochem Mol Biol
January 2025
Programa de Pós-Graduação em Biociências, Universidade do Estado do Rio de Janeiro, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brazil; Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Brazil. Electronic address:
Lipophorin is the primary lipoprotein present in the hemolymph of insects, responsible for the lipids' transport between organs. It interacts with specific sites on cell membranes in an essential process for transferring lipids. The lipophorin receptor is the protein responsible for the interaction between lipophorin and cell membranes.
View Article and Find Full Text PDFBull Entomol Res
November 2024
El Colegio de la Frontera Sur, Unidad Tapachula, Carretera Antiguo Aeropuerto Km. 2.5, Centro, Tapachula, Chiapas, 30700, México.
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