通过其复制蛋白 p88 抑制芜菁花叶病毒的复制。

Repression of turnip crinkle virus replication by its replication protein p88.

机构信息

Department of Plant Pathology, The Ohio State University, Wooster, OH 44691, USA.

Department of Plant Pathology, The Ohio State University, Wooster, OH 44691, USA; Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China.

出版信息

Virology. 2019 Jan 2;526:165-172. doi: 10.1016/j.virol.2018.10.024. Epub 2018 Nov 2.

DOI:10.1016/j.virol.2018.10.024

PMID:30391806

Abstract

We recently reported that p28, one of the two turnip crinkle virus (TCV) replication proteins, trans-complemented a defective TCV lacking p28, yet repressed the replication of another TCV replicon encoding wild-type p28 (Zhang et al., 2017). Here we show that p88, the TCV-encoded RNA-dependent RNA polymerase, likewise trans-complemented a p88-defective TCV replicon, but repressed one encoding wild-type p88. Surprisingly, lowering p88 protein levels enhanced trans-complementation, but weakened repression. Repression by p88 was not simply due to protein over-expression, as deletion mutants missing 127 or 224 N-terminal amino acids accumulated to higher levels but were poor repressors. Finally, both trans-complementation and repression by p88 were accompanied by preferential accumulation of subgenomic RNA2, and a novel class of small TCV RNAs. Our results suggest that repression of TCV replication by p88 may manifest a viral mechanism that regulates the ratio of genomic and subgenomic RNAs based on p88 abundance.

摘要

我们最近报道称，芜菁黄花叶病毒（TCV）的两种复制蛋白之一 p28 可转互补缺乏 p28 的缺陷型 TCV，但会抑制另一种编码野生型 p28 的 TCV 复制子的复制（Zhang 等人，2017）。在这里，我们发现 TCV 编码的 RNA 依赖性 RNA 聚合酶 p88 同样可以转互补 p88 缺陷型 TCV 复制子，但会抑制编码野生型 p88 的复制子。令人惊讶的是，降低 p88 蛋白水平会增强转互补作用，但会削弱抑制作用。p88 的抑制作用并非仅仅由于蛋白过表达所致，因为缺失 127 或 224 个 N 端氨基酸的缺失突变体积累到更高水平，但抑制作用较差。最后，p88 的转互补和抑制作用都伴随着亚基因组 RNA2 和一类新的 TCV 小 RNA 的优先积累。我们的结果表明，p88 对 TCV 复制的抑制作用可能表现出一种病毒机制，根据 p88 丰度调节基因组和亚基因组 RNA 的比例。