title: Sequential recruitment of the endoplasmic reticulum and chloroplasts for plant potyvirus replication.
abstract: The replication of positive-strand RNA viruses occurs in cytoplasmic membrane-bound virus replication complexes (VRCs). Depending on the virus, distinct cellular organelles such as the endoplasmic reticulum (ER), chloroplast, mitochondrion, endosome, and peroxisome are recruited for the formation of VRC-associated membranous structures. Previously, the 6,000-molecular-weight protein (6K) of plant potyviruses was shown to be an integral membrane protein that induces the formation of 6K-containing membranous vesicles at endoplasmic reticulum (ER) exit sites for potyvirus genome replication. Here, we present evidence that the 6K-induced vesicles predominantly target chloroplasts, where they amalgamate and induce chloroplast membrane invaginations. The vesicular transport pathway and actomyosin motility system are involved in the trafficking of the 6K vesicles from the ER to chloroplasts. Viral RNA, double-stranded RNA, and viral replicase components are concentrated at the 6K vesicles that associate with chloroplasts in infected cells, suggesting that these chloroplast-bound 6K vesicles are the site for potyvirus replication. Taken together, these results suggest that plant potyviruses sequentially recruit the ER and chloroplasts for their genome replication.
authors.affiliation: Southern Crop Protection and Food Research Centre, AAFC, 1391 Sandford Street, London, Ontario N5V 4T3, Canada.
authors.forename: Taiyun
authors.initials: T
authors.lastname: Wei
authors.forename: Tyng-Shyan
authors.initials: TS
authors.lastname: Huang
authors.forename: Jamie
authors.initials: J
authors.lastname: McNeil
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Laliberté
authors.forename: Jian
authors.initials: J
authors.lastname: Hong
authors.forename: Richard S
authors.initials: RS
authors.lastname: Nelson
authors.forename: Aiming
authors.initials: A
authors.lastname: Wang
mesh_terms: D002736:Chloroplasts / Q000378:metabolism*; D022162:Cytoplasmic Vesicles / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D007425:Intracellular Membranes / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D018515:Plant Leaves / Q000821:virology; D010942:Plant Viruses / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D017800:Potyvirus / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014026:Nicotiana / Q000821:virology; D014764:Viral Proteins / Q000378:metabolism; D014779:Virus Replication
chemical_list: D008565:Membrane Proteins; D014764:Viral Proteins