title: Tula hantavirus triggers pro-apoptotic signals of ER stress in Vero E6 cells.
abstract: Tula virus is a member of the Hantavirus genus of the family Bunyaviridae. Viruses of this family have an unusual pattern of intracellular maturation at the ER-Golgi compartment. We recently found that Tula virus, similar to several other hantaviruses, is able to induce apoptosis in cultured cells [Li, X.D., Kukkonen, S., Vapalahti, O., Plyusnin, A., Lankinen, H., Vaheri, A., 2004. Tula hantavirus infection of Vero E6 cells induces apoptosis involving caspase 8 activation. J. Gen. Virol. 85, 3261-3268.]. However, the cellular mechanisms remain to be clarified. In this study, we demonstrate that the progressive replication of Tula virus in Vero E6 cells initiates several death programs that are intimately associated with ER stress: (1) early activation of ER-resident caspase-12; (2) phosphorylation of Jun NH2-terminal kinase (JNK) and its downstream target transcriptional factor, c-jun; (3) induction of the pro-apoptotic transcriptional factor, growth arrest- and DNA damage-inducible gene 153, or C/EBP homologous protein (Gadd153/chop); and (4) changes in the ER-membrane protein BAP31 implying cross-talk with the mitochondrial apoptosis pathway. Furthermore, we confirmed that a sustained ER stress was induced marked by an increased expression of an ER chaperone Grp78/BiP. Taken together, we have identified involvement of ER stress-mediated death program in Tula virus-infected Vero E6 cells which provides a new approach to understand the mechanisms in hantavirus-induced apoptosis.
authors.affiliation: Department of Virology, Haartman Institute, PO Box 21, FIN-00014, University of Helsinki, Finland. Xiaodong.Li@Helsinki.Fi
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Li
authors.forename: Hilkka
authors.initials: H
authors.lastname: Lankinen
authors.forename: Niina
authors.initials: N
authors.lastname: Putkuri
authors.forename: Olli
authors.initials: O
authors.lastname: Vapalahti
authors.forename: Antti
authors.initials: A
authors.lastname: Vaheri
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D053454:Caspase 12; D020169:Caspases / Q000378:metabolism; D002522:Chlorocebus aethiops; D004721:Endoplasmic Reticulum / Q000378:metabolism / Q000502:physiology*; D005786:Gene Expression Regulation / Q000502:physiology*; D006476:Orthohantavirus / Q000502:physiology*; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D014709:Vero Cells
chemical_list: D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases; D053454:Caspase 12; D020169:Caspases