title: Novel Mutant AAV2 Rep Proteins Support AAV2 Replication without Blocking HSV-1 Helpervirus Replication.
abstract: As their names imply, parvoviruses of the genus Dependovirus rely for their efficient replication on the concurrent presence of a helpervirus, such as herpesvirus, adenovirus, or papilloma virus. Adeno-associated virus 2 (AAV2) is such an example, which in turn can efficiently inhibit the replication of each helpervirus by distinct mechanisms. In a previous study we have shown that expression of the AAV2 rep gene is not compatible with efficient replication of herpes simplex virus 1 (HSV-1). In particular, the combined DNA-binding and ATPase/helicase activities of the Rep68/78 proteins have been shown to exert opposite effects on the replication of AAV2 and HSV-1. While essential for AAV2 DNA replication these protein activities account for the Rep-mediated inhibition of HSV-1 replication. Here, we describe a novel Rep mutant (Rep-D371Y), which displayed an unexpected phenotype. Rep-D371Y did not block HSV-1 replication, but still supported efficient AAV2 replication, at least when a double-stranded AAV2 genome template was used. We also found that the capacity of Rep-D371Y to induce apoptosis and a Rep-specific DNA damage response was significantly reduced compared to wild-type Rep. These findings suggest that AAV2 Rep-helicase subdomains exert diverging activities, which contribute to distinct steps of the AAV2 life cycle. More important, the novel AAV2 mutant Rep-D371Y may allow deciphering yet unsolved activities of the AAV2 Rep proteins such as DNA second-strand synthesis, genomic integration or packaging, which all involve the Rep-helicase activity.
authors.affiliation: Institute of Virology, University of Zurich, Zurich, Switzerland.|Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, United States of America.
authors.forename: Michael
authors.initials: M
authors.lastname: Seyffert
authors.affiliation: Institute of Virology, University of Zurich, Zurich, Switzerland.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Glauser
authors.affiliation: Institute of Virology, University of Zurich, Zurich, Switzerland.|Institute of Veterinary Anatomy, University of Zurich, Zurich, Switzerland.
authors.forename: Elisabeth M
authors.initials: EM
authors.lastname: Schraner
authors.affiliation: Institute of Virology, University of Zurich, Zurich, Switzerland.
authors.forename: Anna-Paula
authors.initials: AP
authors.lastname: de Oliveira
authors.affiliation: Center for Cell Engineering, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America.
authors.forename: Jorge
authors.initials: J
authors.lastname: Mansilla-Soto
authors.affiliation: Institute of Virology, University of Zurich, Zurich, Switzerland.
authors.forename: Bernd
authors.initials: B
authors.lastname: Vogt
authors.affiliation: Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.|Institute for Experimental Hematology, Hannover Medical School, Hannover, Germany.
authors.forename: Hildegard
authors.initials: H
authors.lastname: Büning
authors.affiliation: Department of Infectious Diseases, King's College London, London, United Kingdom.
authors.forename: R Michael
authors.initials: RM
authors.lastname: Linden
authors.affiliation: Institute of Virology, University of Zurich, Zurich, Switzerland.
authors.forename: Mathias
authors.initials: M
authors.lastname: Ackermann
authors.affiliation: Institute of Virology, University of Zurich, Zurich, Switzerland.
authors.forename: Cornel
authors.initials: C
authors.lastname: Fraefel
mesh_terms: D000818:Animals; D002522:Chlorocebus aethiops; D004265:DNA Helicases / Q000378:metabolism; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D000229:Dependovirus / Q000235:genetics* / Q000378:metabolism; D018259:Herpesvirus 1, Human / Q000235:genetics* / Q000378:metabolism; D014709:Vero Cells; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism; D014779:Virus Replication
chemical_list: D004268:DNA-Binding Proteins; D014764:Viral Proteins; C068734:rep proteins, Adeno-associated virus 2; D004265:DNA Helicases