Chergintsev Denis A, Solovieva Anna D, Atabekova Anastasia K, Lezzhov Alexander A, Golyshev Sergei A, Morozov Sergey Y, Solovyev Andrey G
A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia.
Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia.
Int J Mol Sci. 2023 Sep 15;24(18):14144. doi: 10.3390/ijms241814144.
To move from cell to cell through plasmodesmata, many plant viruses require the concerted action of two or more movement proteins (MPs) encoded by transport gene modules of virus genomes. A tetra-cistron movement block (TCMB) is a newly discovered transport module comprising four genes. TCMB encodes three proteins, which are similar to MPs of the transport module known as the "triple gene block", and a protein unrelated to known viral MPs and containing a double-stranded RNA (dsRNA)-binding domain similar to that found in a family of cell proteins, including AtDRB4 and AtHYL1. Here, the latter TCMB protein, named vDRB for virus dsRNA-binding protein, is shown to bind both dsRNA and single-stranded RNA in vitro. In a turnip crinkle virus-based assay, vDRB exhibits the properties of a viral suppressor of RNA silencing (VSR). In the context of potato virus X infection, vDRB significantly decreases the number and size of "dark green islands", regions of local antiviral silencing, supporting the VSR function of vDRB. Nevertheless, vDRB does not exhibit the VSR properties in non-viral transient expression assays. Taken together, the data presented here indicate that vDRB is an RNA-binding protein exhibiting VSR functions in the context of viral infection.
许多植物病毒要通过胞间连丝在细胞间移动，需要病毒基因组转运基因模块编码的两种或更多种运动蛋白（MP）协同发挥作用。四顺反子运动阻断（TCMB）是新发现的一种由四个基因组成的转运模块。TCMB编码三种与被称为“三基因块”的转运模块的MP相似的蛋白质，以及一种与已知病毒MP无关、含有与包括AtDRB4和AtHYL1在内的一类细胞蛋白中发现的双链RNA（dsRNA）结合结构域相似的蛋白质。在这里，后一种TCMB蛋白，即病毒dsRNA结合蛋白（vDRB），在体外被证明能结合dsRNA和单链RNA。在基于芜菁皱缩病毒的试验中，vDRB表现出RNA沉默病毒抑制子（VSR）的特性。在马铃薯X病毒感染的情况下，vDRB显著减少了局部抗病毒沉默区域“深绿岛”的数量和大小，支持了vDRB的VSR功能。然而，vDRB在非病毒瞬时表达试验中未表现出VSR特性。综上所述，本文提供的数据表明vDRB是一种在病毒感染情况下具有VSR功能的RNA结合蛋白。
