Location: Foreign Animal Disease Research
Title: Host Cell Factors Involved in the Life Cycle of FMDV Authors
Submitted to: European Study Group on the Molecular Biology of Picornaviruses
Publication Type: Abstract Only
Publication Acceptance Date: April 3, 2008
Publication Date: May 26, 2008
Citation: Lawrence, P., Rieder, A.E. 2008. Host Cell Factors Involved in the Life Cycle of FMDV. European Study Group on the Molecular Biology of Picornaviruses. P 85 Technical Abstract: Foot-and-Mouth Disease Virus (FMDV), like other RNA viruses, recruits various host cell factors to assist in translation and replication of the virus genome. While FMDV translation has been extensively investigated, much remains unknown regarding replication of the positive-sense RNA genome. In this study we investigated the role of RNA helicase-A (RHA, also known as DHX9, DDX9, and NDHII) on FMDV replication in cells. Specifically, gene-specific siRNA constructs were utilized to knockdown RHA expression in cell culture. Treatment of cells with either one or a combination of RHA-specific siRNAs reduced the expression of this protein and rendered these cells partially resistant to infection with FMDV A24-Cruzeiro. In contrast, no significant reduction on virus titers was observed when the cells were treated with non-specific siRNA as a control. Using immunofluorescent microscopy, we found that prior to infection, RHA localizes to the nucleus. However, as the virus infection proceeds, a change in the distribution of RHA is detected. At 3 hours post-infection (MOI 5-10), RHA is also present in the cytoplasm within the perinuclear region, where viral proteins of the replication complex also co-localize (2C, 3A, and 3D pol). The results also indicated that Sam68, (the 68 kDa Src-associated in mitosis protein) is recruited to the site of replication, suggesting the participation of this protein in FMDV infection. Current efforts to produce these protein factors in a purified form will facilitate studies of protein-protein and RNA-protein interaction and will assist in the development of a detailed model of the host cell proteins that facilitate RNA replication during FMDV infection.