This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Jacob-Wilk, D. Articles by Van Alfen, N. K. Search for Related Content PubMed PubMed Citation Articles by Jacob-Wilk, D. Articles by Van Alfen, N. K.

 Previous Article  |  Next Article 

Journal of Virology, July 2006, p. 6588-6596, Vol. 80, No. 13
0022-538X/06/$08.00+0     doi:10.1128/JVI.02519-05
Copyright © 2006, American Society for Microbiology. All Rights Reserved.

Mycovirus Cryphonectria Hypovirus 1 Elements Cofractionate with trans-Golgi Network Membranes of the Fungal Host Cryphonectria parasitica

Debora Jacob-Wilk,^* Massimo Turina, and Neal K. Van Alfen

Department of Plant Pathology, College of Agricultural and Environmental Science, One Shields Avenue, University of California, Davis, Davis, California 95616

Received 1 December 2005/ Accepted 9 April 2006

The mycovirus cryphonectria hypovirus 1 (CHV1) causes proliferation of vesicles in its host, Cryphonectria parasitica, the causal agent of chestnut blight. These vesicles have previously been shown to contain both CHV1 genomic double-stranded RNA (dsRNA) and RNA polymerase activity. To determine the cellular origins of these virus-induced membrane structures, we compared the fractionation of several cellular and viral markers. Results showed that viral dsRNA, helicase, polymerase, and protease p29 copurify with C. parasitica trans-Golgi network (TGN) markers, suggesting that the virus utilizes the fungal TGN for replication. We also show that the CHV1 protease p29 associates with vesicle membranes and is resistant to treatments that would release peripheral membrane proteins. Thus, p29 behaves as an integral membrane protein of the vesicular fraction derived from the fungal TGN. Protease p29 was also found to be fully susceptible to proteolytic digestion in the absence of detergent and, thus, is wholly or predominantly on the cytoplasmic face of the vesicles. Fractionation analysis of p29 deletion variants showed that sequences in the C terminal of p29 mediate membrane association. In particular, the C-terminal portion of the protein (Met-135-Gly-248) is sufficient for membrane association and is enough to direct p29 to the TGN vesicles in the absence of other viral elements.

Present address: Istituto di Virologia Vegetale, CNR Torino, Strada delle Cacce 73, 10135 Torino, Italy.

This article has been cited by other articles:

• Faruk, M. I., Eusebio-Cope, A., Suzuki, N. (2008). A Host Factor Involved in Hypovirus Symptom Expression in the Chestnut Blight Fungus, Cryphonectria parasitica. J. Virol. 82: 740-754 [Abstract] [Full Text]  
• Sun, L., Nuss, D. L., Suzuki, N. (2006). Synergism between a mycoreovirus and a hypovirus mediated by the papain-like protease p29 of the prototypic hypovirus CHV1-EP713. J. Gen. Virol. 87: 3703-3714 [Abstract] [Full Text]