title: Chlorella viruses prevent multiple infections by depolarizing the host membrane.
abstract: Previous experiments established that when the unicellular green alga Chlorella NC64A is inoculated with two viruses, usually only one virus replicates in a single cell. That is, the viruses mutually exclude one another. In the current study, we explore the possibility that virus-induced host membrane depolarization, at least partially caused by a virus-encoded K(+) channel (Kcv), is involved in this mutual exclusion. Two chlorella viruses, PBCV-1 and NY-2A, were chosen for the study because (i) they can be distinguished by real-time PCR and (ii) they exhibit differential sensitivity to Cs(+), a well-known K(+) channel blocker. PBCV-1-induced host membrane depolarization, Kcv channel activity and plaque formation are only slightly affected by Cs(+), whereas all three NY-2A-induced events are strongly inhibited by Cs(+). The addition of one virus 5-15 min before the other results primarily in replication of the first virus. However, if virus NY-2A-induced membrane depolarization of the host is blocked by Cs(+), PBCV-1 is not excluded. We conclude that virus-induced membrane depolarization is at least partially responsible for the exclusion phenomenon.
authors.affiliation: Institute of Botany TU-Darmstadt, Schnittspahnstrasse 3, 64287 Darmstadt, Germany.
authors.forename: Timo
authors.initials: T
authors.lastname: Greiner
authors.affiliation: Institute of Botany TU-Darmstadt, Schnittspahnstrasse 3, 64287 Darmstadt, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Frohns
authors.affiliation: Department of Plant Pathology and Nebraska Center for Virology, 205 Morrison Hall, University of Nebraska, Lincoln, NE 68583-0900, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Kang
authors.affiliation: Department of Plant Pathology and Nebraska Center for Virology, 205 Morrison Hall, University of Nebraska, Lincoln, NE 68583-0900, USA.
authors.forename: James L
authors.initials: JL
authors.lastname: Van Etten
authors.affiliation: Institute of Botany TU-Darmstadt, Schnittspahnstrasse 3, 64287 Darmstadt, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Käsmann
authors.affiliation: Department of Biology and CNR IBF-Mi, and Istituto Nazionale di Fisica della Materia, Università degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Moroni
authors.affiliation: Institute of Botany TU-Darmstadt, Schnittspahnstrasse 3, 64287 Darmstadt, Germany.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Hertel
authors.affiliation: Institute of Botany TU-Darmstadt, Schnittspahnstrasse 3, 64287 Darmstadt, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Thiel
mesh_terms: D002462:Cell Membrane / Q000502:physiology*; D002708:Chlorella / Q000821:virology*; D008564:Membrane Potentials; D017862:Phycodnaviridae / Q000254:growth & development / Q000502:physiology*; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000378:metabolism; D010948:Viral Plaque Assay; D014764:Viral Proteins / Q000378:metabolism
chemical_list: D026902:Potassium Channel Blockers; D015221:Potassium Channels; D014764:Viral Proteins