Chen Hsin-Chuan, Hsu Yau-Heiu, Lin Na-Sheng
Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 114, Taiwan, ROC.
Virology. 2007 Sep 1;365(2):271-84. doi: 10.1016/j.virol.2007.03.050. Epub 2007 May 4.
Satellite RNAs associated with Bamboo mosaic virus (satBaMV) exhibit different phenotypes. Some isolates could reduce the accumulation of BaMV RNA and attenuate the BaMV-induced symptoms in co-inoculated plants. The determinants of the downregulation of BaMV replication were mapped in the 5' hypervariable region of satBaMV, which folds into a conserved apical hairpin stem loop (AHSL) structure comprising an apical loop and two internal loops, as evidenced by enzymatic probing. We also demonstrated that the integrity of the AHSL structure of interfering satBaMV was essential for the interference of BaMV accumulation. Concurrent analyses of natural satBaMV isolates revealed that all of the interfering isolates contained the same structures and sequences in the internal loops. Further, refined analyses indicated that, besides the AHSL structure, specific nucleotides in the internal loops play a crucial role in the downregulation, which implies that they may be required for the interaction of viral/cellular factors in this process.
与竹花叶病毒相关的卫星RNA（satBaMV）表现出不同的表型。一些分离株能够减少BaMV RNA的积累，并减轻共接种植物中BaMV诱导的症状。BaMV复制下调的决定因素定位在satBaMV的5'高变区，该区域折叠成一个保守的顶端发夹茎环（AHSL）结构，包括一个顶端环和两个内环，酶切探测证明了这一点。我们还证明，干扰性satBaMV的AHSL结构完整性对于干扰BaMV积累至关重要。对天然satBaMV分离株的同时分析表明，所有干扰性分离株在内环中都含有相同的结构和序列。此外，精细分析表明，除了AHSL结构外，内环中的特定核苷酸在下调过程中起着关键作用，这意味着它们可能是该过程中病毒/细胞因子相互作用所必需的。
