Chlorella viruses prevent multiple infections by depolarizing the host membrane.
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.
Greiner
Timo
T
Institute of Botany TU-Darmstadt, Schnittspahnstrasse 3, 64287 Darmstadt, Germany.
Frohns
Florian
F
Institute of Botany TU-Darmstadt, Schnittspahnstrasse 3, 64287 Darmstadt, Germany.
Kang
Ming
M
Department of Plant Pathology and Nebraska Center for Virology, 205 Morrison Hall, University of Nebraska, Lincoln, NE 68583-0900, USA.
Van Etten
James L
JL
Department of Plant Pathology and Nebraska Center for Virology, 205 Morrison Hall, University of Nebraska, Lincoln, NE 68583-0900, USA.
Käsmann
Anja
A
Institute of Botany TU-Darmstadt, Schnittspahnstrasse 3, 64287 Darmstadt, Germany.
Moroni
Anna
A
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.
Hertel
Brigitte
B
Institute of Botany TU-Darmstadt, Schnittspahnstrasse 3, 64287 Darmstadt, Germany.
Thiel
Gerhard
G
Institute of Botany TU-Darmstadt, Schnittspahnstrasse 3, 64287 Darmstadt, Germany.
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
D026902:Potassium Channel Blockers; D015221:Potassium Channels; D014764:Viral Proteins