Effect of mutations in the 2b protein of tomato aspermy virus on RNA silencing suppressor activity, virulence, and virus-induced gene silencing
Effect of mutations in the 2b protein of tomato aspermy virus on RNA silencing suppressor activity, virulence, and virus-induced gene silencing
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DOI：
10.1007/s00705-021-05344-z
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发表时间：
2022-01-03
影响因子：
2.7
通讯作者：
Mochizuki, Tomofumi
中科院分区：
文献类型：
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作者：
Murai, Hirotomo;Atsumaru, Kenta;Mochizuki, Tomofumi
番茄无精病毒（TAV）和黄瓜花叶病毒（CMV）属于雀麦花叶病毒科（Bromoviridae）中的黄瓜花叶病毒属（Cucumovirus）。黄瓜病毒2b蛋白是最早发现的RNA沉默（VSR）抑制因子之一。黄瓜病毒2b蛋白含有由几个高度保守的氨基酸残基组成的保守氨基酸基序。在这里，我们证明了TAV 2b蛋白N-末端区域，Arg 46，Ser 40和Ser 42以及CMV 2b蛋白是VSR活性，毒力和病毒RNA积累所必需的。此外，我们开发了第一个TAV诱导的基因沉默（VIGS）载体。与其他黄瓜病毒载体如CMV和花生矮化病毒相比，TAV载体在本氏烟草中当2b蛋白VSR活性保留时不诱导沉默表型。这些发现表明，黄瓜病毒2b蛋白共享VSR活性的氨基酸残基，但可能在VIGS诱导中具有不同的作用。
Tomato aspermy virus (TAV) and cucumber mosaic virus ( CMV) belong to the genus Cucumovirus in the family Bromoviridae. The cucumovirus 2b protein is one of the first identified viral suppressors of RNA silencing (VSR). The cucumovirus 2b protein contains a conserved amino acid motif consisting of several highly conserved amino acid residues. Here, we demonstrate that the TAV 2b protein N-terminal region, Arg46, Ser40, and Ser42 as well as the CMV 2b protein are essential for VSR activity, virulence, and viral RNA accumulation. Furthermore, we developed the first TAV-induced gene silencing (VIGS) vector. In contrast to other cucumovirus vectors, such as CMV and peanut stunt virus, the TAV vector did not induce a silencing phenotype in Nicotiana benthamiana when 2b protein VSR activity was retained. These findings suggest that the cucumovirus 2b proteins share amino acid residues for VSR activity but may have different roles in VIGS induction.