title: Geminivirus Activates ASYMMETRIC LEAVES 2 to Accelerate Cytoplasmic DCP2-Mediated mRNA Turnover and Weakens RNA Silencing in Arabidopsis.
abstract: Aberrant viral RNAs produced in infected plant cells serve as templates for the synthesis of dsRNAs. The derived virus-related small interfering RNAs (siRNA) mediate cleavage of viral RNAs by post-transcriptional gene silencing (PTGS), thus blocking virus multiplication. Here, we identified ASYMMETRIC LEAVES2 (AS2) as a new component of plant P body complex which mediates mRNA decapping and degradation. We found that AS2 promotes DCP2 decapping activity, accelerates mRNA turnover rate, inhibits siRNA accumulation and functions as an endogenous suppressor of PTGS. Consistent with these findings, as2 mutant plants are resistant to virus infection whereas AS2 over-expression plants are hypersensitive. The geminivirus nuclear shuttle protein BV1 protein, which shuttles between nuclei and cytoplasm, induces AS2 expression, causes nuclear exit of AS2 to activate DCP2 decapping activity and renders infected plants more sensitive to viruses. These principles of gene induction and shuttling of induced proteins to promote mRNA decapping in the cytosol may be used by viral pathogens to weaken antiviral defenses in host plants.
authors.affiliation: Temasek Life Sciences Laboratory, National University of Singapore, Singapore; State Key laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Ye
authors.affiliation: Laboratory of Plant Molecular Biology, Rockefeller University, New York, New York, United States of America; Institute of Biochemistry, National Chung Hsing University, Taichung, Taiwan.
authors.forename: Junyi
authors.initials: J
authors.lastname: Yang
authors.affiliation: Temasek Life Sciences Laboratory, National University of Singapore, Singapore; State Key laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Yanwei
authors.initials: Y
authors.lastname: Sun
authors.affiliation: State Key laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Pingzhi
authors.initials: P
authors.lastname: Zhao
authors.affiliation: Temasek Life Sciences Laboratory, National University of Singapore, Singapore.
authors.forename: Shiqiang
authors.initials: S
authors.lastname: Gao
authors.affiliation: Laboratory of Plant Molecular Biology, Rockefeller University, New York, New York, United States of America.
authors.forename: Choonkyun
authors.initials: C
authors.lastname: Jung
authors.affiliation: Temasek Life Sciences Laboratory, National University of Singapore, Singapore.
authors.forename: Jing
authors.initials: J
authors.lastname: Qu
authors.affiliation: State Key laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Rongxiang
authors.initials: R
authors.lastname: Fang
authors.affiliation: Laboratory of Plant Molecular Biology, Rockefeller University, New York, New York, United States of America.
authors.forename: Nam-Hai
authors.initials: NH
authors.lastname: Chua
mesh_terms: D017360:Arabidopsis; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D047369:Chromatin Immunoprecipitation; D003593:Cytoplasm / Q000378:metabolism; D004722:Endoribonucleases / Q000235:genetics / Q000378:metabolism*; D017791:Geminiviridae; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D006790:Host-Parasite Interactions / Q000502:physiology*; D015151:Immunoblotting; D010935:Plant Diseases / Q000235:genetics* / Q000276:immunology; D057865:Plant Immunity / Q000502:physiology*; D030821:Plants, Genetically Modified; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger; D034741:RNA, Small Interfering / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: C463739:AS2 protein, Arabidopsis; D029681:Arabidopsis Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D014157:Transcription Factors; D004722:Endoribonucleases; C518494:Dcp2 protein, Arabidopsis