Subcellular localization and expression of bamboo mosaic virus satellite RNA-encoded protein

• Published in: Journal of general virology 2009-02, Vol.90 (2), p.507-518
• Main Authors: Palani, Paramasivan Vijaya, Chiu, Morgan, Chen, Wei, Wang, Ching-Chi, Lin, Choy-Chieng, Hsu, Chuen-Chi, Cheng, Chi-Ping, Chen, Chung-Mong, Hsu, Yau-Heiu, Lin, Na-Sheng
• Format: Article
• Language: English
• Subjects: Bamboo mosaic virus; Bambusa; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Microbiology; Miscellaneous; Mosaic Viruses - genetics; Nicotiana benthamiana; Open Reading Frames; Plant; Plant Leaves - virology; RNA, Satellite - genetics; RNA, Viral - genetics; RNA, Viral - isolation & purification; Sasa - virology; Transcription, Genetic; Viral Nonstructural Proteins - genetics; Viral Proteins - genetics; Viral Proteins - isolation & purification; Virology
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/vir.0.004994-0

1 Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan 115, ROC 2 Graduate Institute of Biotechnology, National Chung-Hsing University, Taichung, Taiwan 402, ROC 3 Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan 115, ROC Correspondence Na-Sheng Lin nslin{at}sinica.edu.tw The satellite RNA of bamboo mosaic virus (satBaMV) has a single open reading frame encoding a non-structural protein, P20, which facilitates long-distance movement of satBaMV in BaMV and satBaMV co-infected plants. Immunohistochemistry and immunoelectron microscopy revealed that the P20 protein accumulated in the cytoplasm and nuclei in co-infected cells. P20 and the helper virus coat protein (CP) were highly similar in their subcellular localization, except that aggregates of BaMV virions were not labelled with anti-P20 serum. The BaMV CP protein was fairly abundant in mesophyll cells, whilst P20 was more frequently detected in mesophyll cells and vascular tissues. The expression kinetics of the P20 protein was similar to but slightly earlier than that of CP in co-infected Bambusa oldhamii protoplasts and Nicotiana benthamiana leaves. However, satBaMV-encoded protein levels declined rapidly in the late phase of co-infection. During co-infection, in addition to the intact P20, a low-molecular-mass polypeptide of 16 kDa was identified as a P20 C-terminally truncated product; the possible method of generation of the truncated protein is discussed.