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 Lin, Y.-J. Articles by Wu, S.-C. Search for Related Content PubMed PubMed Citation Articles by Lin, Y.-J. Articles by Wu, S.-C.

 Previous Article  |  Next Article 

Journal of Virology, July 2005, p. 8535-8544, Vol. 79, No. 13
0022-538X/05/$08.00+0     doi:10.1128/JVI.79.13.8535-8544.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Histidine at Residue 99 and the Transmembrane Region of the Precursor Membrane prM Protein Are Important for the prM-E Heterodimeric Complex Formation of Japanese Encephalitis Virus

Institute of Biotechnology, Department of Life Science, National Tsing-Hua University, Hsinchu 30013, Taiwan, Republic of China

Received 13 January 2005/ Accepted 7 March 2005

The formation of the flavivirus prM-E complex is an important step for the biogenesis of immature virions, which is followed by a subsequent cleavage of prM to M protein through cellular protease to result in the production and release of mature virions. In this study, the intracellular formation of the prM-E complex of Japanese encephalitis virus was investigated by baculovirus coexpression of prM and E in trans in Sf9 insect cells as analyzed by anti-E antibody immunoprecipitation and sucrose gradient sedimentation analysis. A series of carboxyl-terminally truncated prM mutant baculoviruses was constructed to demonstrate that the truncations of the transmembrane (TM) region resulted in a reduction of the formation of the stable prM-E complex by approximately 40% for the TM1 (at residues 130 to 147 [prM130-147]) truncation and 20% for TM2 (at prM153-167) truncation. Alanine-scanning site-directed mutagenesis on the prM99-103 region indicated that the His99 residue was the critical prM binding element for stable prM-E heterodimeric complex formation. The single amino acid mutation at the His99 residue of prM abolishing the prM-E interaction was not due to reduced expression or different subcellular location of the mutant prM protein involved in prM-E interactions as characterized by pulse-chase labeling and confocal scanning microscopic analysis. Recombinant subviral particles were detected in the Sf9 cell culture supernatants by baculovirus coexpression of prM and E proteins but not with the prM H99A mutant. Sequence alignment analysis was further conducted with different groups of flaviviruses to show that the prM H99 residues are generally conserved. Our findings are the first report to characterize the minimum binding elements of the prM protein that are involved in prM-E interactions of flaviviruses. This information, concerning a molecular framework for the prM protein, is considered to elucidate the structure/function relationship of the prM-E complex synthesis and provide the proper trajectory for flavivirus assembly and maturation.

This article has been cited by other articles:

• Li, L., Lok, S.-M., Yu, I-M., Zhang, Y., Kuhn, R. J., Chen, J., Rossmann, M. G. (2008). The Flavivirus Precursor Membrane-Envelope Protein Complex: Structure and Maturation. Science 319: 1830-1834 [Abstract] [Full Text]