Chlorella virus MT325 encodes water and potassium channels that interact synergistically

Authors

Sabrina Gazzarrini, Università degli Studi di Milano
Ming Kang, University of Nebraska-LincolnFollow
Svetlana Epimashko, Università degli Studi di Milano
James L. Van Etten, University of Nebraska - LincolnFollow
Jack Dainty, University of Toronto
Gerhard Thiel, Darmstadt University of TechnologyFollow
Anna Moroni, Università degli Studi di MilanoFollow

Date of this Version

2-2006

Document Type

Article

Citation

PNAS, April 4, 2006, vol. 103, no. 14, pp. 5355–5360.

Comments

© 2006 by The National Academy of Sciences of the USA. Used by permission.

Abstract

Fast and selective transport of water through cell membranes is facilitated by water channels. Water channels belonging to the major intrinsic proteins (MIPs) family have been found in all three domains of life, Archaea, Bacteria, and Eukarya. Here we show that Chlorella virus MT325 has a water channel gene, aqpv1, that forms a functional aquaglyceroporin in oocytes. aqpv1 is transcribed during infection together with MT325 kcv, a gene encoding a previously undescribed type of viral potassium channel. Coexpression of AQPV1 and MT325-Kcv in Xenopus oocytes synergistically increases water transport, suggesting a possible concerted action of the two channels in the infection cycle. The two channels operate by a thermodynamically coupled mechanism that simultaneously alters water conductance and driving force for water movement. Considering the universal role of osmosis, this mechanism is relevant to any cell coexpressing water and potassium channels and could have pathological as well as basic physiological relevance.