title: Rice black-streaked dwarf virus minor core protein P8 is a nuclear dimeric protein and represses transcription in tobacco protoplasts.
abstract: Virus-encoding nuclear transcriptional regulators play important roles in the viral life cycle. Most of these proteins exhibit intrinsic transcriptional activation or repression activity, and are involved in the regulation of the expression of virus genome itself or important cellular genes to facilitate viral replication and inhibit antiviral responses. Here, we report that the minor core protein P8 of Rice black-streaked dwarf virus, a dsRNA virus infecting host plants and insects, is targeted to the nucleus of insect and plant cells via its N-terminal 1-40 amino acids and possesses potent active transcriptional repression activity in Bright Yellow-2 tobacco suspension cells. Moreover, P8, like many transcriptional regulatory proteins, is capable of forming homo-dimers within insect cells and in vitro. All these data suggest that P8 is likely to enter the nucleus of host cell and play an important role as a negative transcriptional regulator of host gene expression during the process of virus-host interaction.
authors.affiliation: Peking-Yale Joint Center for Plant Molecular Genetics and Agrobiotechnology, The National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Liu
authors.forename: Chunhong
authors.initials: C
authors.lastname: Wei
authors.forename: Yongwang
authors.initials: Y
authors.lastname: Zhong
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
mesh_terms: D000818:Animals; D019281:Dimerization; D015967:Gene Expression Regulation, Viral; D017930:Genes, Reporter; D007313:Insecta / Q000821:virology; D010942:Plant Viruses / Q000235:genetics / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011523:Protoplasts / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015183:Restriction Mapping; D014026:Nicotiana / Q000235:genetics* / Q000821:virology; D014158:Transcription, Genetic; D014758:Viral Core Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D011993:Recombinant Fusion Proteins; D014758:Viral Core Proteins