文章基本信息

标题：A positive-feedback mechanism promotes reovirus particle conversion to the intermediate associated with membrane penetration
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作者：Melina A. Agosto ; Kimberly S. Myers ; Tijana Ivanovic 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2008
卷号：105
期号：30
页码：10571-10576
DOI：10.1073/pnas.0802039105
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Membrane penetration by reovirus is associated with conversion of a metastable intermediate, the ISVP, to a further-disassembled particle, the ISVP*. Factors that promote this conversion in cells are poorly understood. Here, we report the in vitro characterization of a positive-feedback mechanism for promoting ISVP* conversion. At high particle concentration, conversion approximated second-order kinetics, and products of the reaction operated in trans to promote the conversion of target ISVPs. Pore-forming peptide 1N, which is released from particles during conversion, was sufficient for promoting activity. A mutant that does not undergo 1N release failed to exhibit second-order conversion kinetics and also failed to promote conversion of wild-type target ISVPs. Susceptibility of target ISVPs to promotion in trans was temperature dependent and correlated with target stability, suggesting that capsid dynamics are required to expose the interacting epitope. A positive-feedback mechanism of promoting escape from the metastable intermediate has not been reported for other viruses but represents a generalizable device for sensing a confined volume, such as that encountered during cell entry.
关键词：cell entry ; heat inactivation ; nonenveloped virus ; Reoviridae