title: GAPDH--a recruits a plant virus movement protein to cortical virus replication complexes to facilitate viral cell-to-cell movement.
abstract: The formation of virus movement protein (MP)-containing punctate structures on the cortical endoplasmic reticulum is required for efficient intercellular movement of Red clover necrotic mosaic virus (RCNMV), a bipartite positive-strand RNA plant virus. We found that these cortical punctate structures constitute a viral replication complex (VRC) in addition to the previously reported aggregate structures that formed adjacent to the nucleus. We identified host proteins that interacted with RCNMV MP in virus-infected Nicotiana benthamiana leaves using a tandem affinity purification method followed by mass spectrometry. One of these host proteins was glyceraldehyde 3-phosphate dehydrogenase-A (NbGAPDH-A), which is a component of the Calvin-Benson cycle in chloroplasts. Virus-induced gene silencing of NbGAPDH-A reduced RCNMV multiplication in the inoculated leaves, but not in the single cells, thereby suggesting that GAPDH-A plays a positive role in cell-to-cell movement of RCNMV. The fusion protein of NbGAPDH-A and green fluorescent protein localized exclusively to the chloroplasts. In the presence of RCNMV RNA1, however, the protein localized to the cortical VRC as well as the chloroplasts. Bimolecular fluorescence complementation assay and GST pulldown assay confirmed in vivo and in vitro interactions, respectively, between the MP and NbGAPDH-A. Furthermore, gene silencing of NbGAPDH-A inhibited MP localization to the cortical VRC. We discuss the possible roles of NbGAPDH-A in the RCNMV movement process.
authors.affiliation: Laboratory of Plant Pathology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Kaido
authors.affiliation: Laboratory of Plant Pathology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
authors.forename: Kazutomo
authors.initials: K
authors.lastname: Abe
authors.affiliation: Laboratory of Plant Pathology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Mine
authors.affiliation: Laboratory of Plant Pathology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
authors.forename: Kiwamu
authors.initials: K
authors.lastname: Hyodo
authors.affiliation: Institute for Enzyme Research, The University of Tokushima, Tokushima, Japan.
authors.forename: Takako
authors.initials: T
authors.lastname: Taniguchi
authors.affiliation: Institute for Enzyme Research, The University of Tokushima, Tokushima, Japan.
authors.forename: Hisaaki
authors.initials: H
authors.lastname: Taniguchi
authors.affiliation: Laboratory of Plant Pathology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Mise
authors.affiliation: Laboratory of Plant Pathology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Okuno
mesh_terms: D002736:Chloroplasts / Q000201:enzymology / Q000235:genetics / Q000821:virology; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating) / Q000096:biosynthesis / Q000235:genetics; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism / Q000821:virology; D019183:Tombusviridae / Q000502:physiology*; D014779:Virus Replication / Q000502:physiology*
chemical_list: D010940:Plant Proteins; D012367:RNA, Viral; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating)