title: The RXL motif of the African cassava mosaic virus Rep protein is necessary for rereplication of yeast DNA and viral infection in plants.
abstract: Geminiviruses, single-stranded DNA plant viruses, encode a replication-initiator protein (Rep) that is indispensable for virus replication. A potential cyclin interaction motif (RXL) in the sequence of African cassava mosaic virus Rep may be an alternative link to cell cycle controls to the known interaction with plant homologs of retinoblastoma protein (pRBR). Mutation of this motif abrogated rereplication in fission yeast induced by expression of wildtype Rep suggesting that Rep interacts via its RXL motif with one or several yeast proteins. The RXL motif is essential for viral infection of Nicotiana benthamiana plants, since mutation of this motif in infectious clones prevented any symptomatic infection. The cell-cycle link (Clink) protein of a nanovirus (faba bean necrotic yellows virus) was investigated that activates the cell cycle by binding via its LXCXE motif to pRBR. Expression of wildtype Clink and a Clink mutant deficient in pRBR-binding did not trigger rereplication in fission yeast.
authors.affiliation: Institut für Biomaterialien und biomolekulare Systeme, Abteilung für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Hipp
authors.affiliation: Institut für Biomaterialien und biomolekulare Systeme, Abteilung für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Rau
authors.affiliation: Institut für Biomaterialien und biomolekulare Systeme, Abteilung für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Schäfer
authors.affiliation: Institut des Sciences du Végétal, CNRS, 91198 Gif-sur-Yvette, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Gronenborn
authors.affiliation: Institut für Biomaterialien und biomolekulare Systeme, Abteilung für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany. Electronic address: holger.jeske@bio.uni-stuttgart.de.
authors.forename: Holger
authors.initials: H
authors.lastname: Jeske
mesh_terms: D020816:Amino Acid Motifs; D053839:Begomovirus / Q000201:enzymology / Q000502:physiology*; D002453:Cell Cycle; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication; D004271:DNA, Fungal / Q000378:metabolism*; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D012568:Schizosaccharomyces / Q000502:physiology / Q000821:virology*; D014026:Nicotiana / Q000821:virology*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*
chemical_list: D004271:DNA, Fungal; D050505:Mutant Proteins; D015534:Trans-Activators; C045264:replication initiator protein; D004265:DNA Helicases
keywords: AC1; Cell cycle; Clink; Geminivirus; Nanovirus; RXL motif; Rep; S. pombe