Identification of RNA helicase A as a new host factor in the replication cycle of foot-and-mouth disease virus.
Foot-and-mouth disease virus (FMDV), as with other RNA viruses, recruits various host cell factors to assist in the translation and replication of the virus genome. In this study, we investigated the role of RNA helicase A (RHA) in the life cycle of FMDV. Immunofluorescent microscopy (IFM) showed a change in the subcellular distribution of RHA from the nucleus to the cytoplasm in FMDV-infected cells as infection progressed. Unlike nuclear RHA, the RHA detected in the cytoplasm reacted with an antibody that recognizes only the nonmethylated form of RHA. In contrast to alterations in the subcellular distribution of nuclear factors observed during infection with the related cardioviruses, cytoplasmic accumulation of RHA did not require the activity of the FMDV leader protein. Using IFM, we have found cytoplasmic RHA in proximity to the viral 2C and 3A proteins, which promotes the assembly of the replication complexes, as well as cellular poly(A) binding protein (PABP). Coimmunoprecipitation assays confirmed that these proteins are complexed with RHA. We have also identified a novel interaction between RHA and the S fragment in the FMDV 5' nontranslated region. Moreover, a reduction in the expression of RHA, using RHA-specific small interfering RNA constructs, inhibited FMDV replication. These results indicate that RHA plays an essential role in the replication of FMDV and potentially other picornaviruses through ribonucleoprotein complex formation at the 5' end of the genome and by interactions with 2C, 3A, and PABP.
Lawrence
Paul
P
Foreign Animal Disease Research Unit, United States Department of Agriculture, Agricultural Research Service, Plum Island Animal Disease Center, Greenport, New York 11944-0848, USA.
Rieder
Elizabeth
E
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D000818:Animals; D002460:Cell Line; D053487:DEAD-box RNA Helicases / Q000235:genetics / Q000378:metabolism*; D005536:Foot-and-Mouth Disease / Q000235:genetics / Q000378:metabolism; D029544:Foot-and-Mouth Disease Virus / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D016679:Genome, Viral; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D039102:Poly(A)-Binding Proteins / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism; D014779:Virus Replication
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D007527:Isoenzymes; D039102:Poly(A)-Binding Proteins; D034741:RNA, Small Interfering; D012367:RNA, Viral; D014764:Viral Proteins; D053487:DEAD-box RNA Helicases