We show that brome mosaic virus (BMV) RNA replication protein 1a, 2a polymerase, and a cis-acting replication signal recapitulate the functions of Gag, Pol, and RNA packaging signals in conventional retrovirus and foamy virus cores. Prior to RNA replication, 1a forms spherules budding into the endoplasmic reticulum membrane, sequestering viral positive-strand RNA templates in a nuclease-resistant, detergent-susceptible state. When expressed, 2a polymerase colocalizes in these spherules, which become the sites of viral RNA synthesis and retain negative-strand templates for positive-strand RNA synthesis. These results explain many features of replication by numerous positive strand RNA viruses and reveal that these viruses, reverse transcribing viruses, and dsRNA viruses share fundamental similarities in replication and may have common evolutionary origins.
|Number of pages||10|
|State||Published - 2002|
Bibliographical noteFunding Information:
We thank Randall Massey and Benjamin August of the University of Wisconsin Medical School Electron Microscope Facility for assistance with electron microscopy, members of our laboratory for helpful discussions, and Bill Sugden and John Young for comments on the manuscript. This research was supported by NIH grant GM35072. P.A. is an Investigator of the Howard Hughes Medical Institute.