Rice stripe virus rapidly establishes infection by interfering with plant protein palmylization

disease caused by rice stripe virus (RSV) is one of the most serious viral diseases in indica production in China and East Asia, and has been endemic in China in recent decades. Professor Zhou Xueping, director of the Institute of Plant Protection of the Chinese Academy of Agricultural Sciences, led the team to further explore the game between RSV and host plants on the basis of the biology, coding protein function and virus disease prevention and control of the virus in the early stages, and found that the virus in the process of co-evolution with plants carefully regulate plant defense protein levels to help the virus quickly establish infection. The results were published online December 9 in the internationally renowned journal
Plant.
virus infects plants, only through the channel between plant cells "intercellular wire" can move between plant cells, to achieve the infestion of plants. Remorin protein is one of the unique proteins of tetanus plants, can be specifically located on the cell membrane lipid raft, by affecting the accumulation ofbodies to regulate the permeability of intercellular wire, equivalent to the control cell wire aperture size gate.
previous studies have found that the protein played an important role in regulating pathogen infestion. Compared with plant pathogenic microorganisms such as fungi and bacteria, the virus genome is small, simple in structure, only encodes a few proteins, wherein the virus-coded motor protein can aid the virus to move between cells, then how does a small plant virus knock on the door of the channel of plant cells through the motion protein?
In order to identify the host factors involved in regulating RSV infested plants and to understand the intrusion process of RSV at the cellular level, Zhou Xueping's team first successfully identified a negative regulatory RSV infested host factor NbREM1, NbREM1 belonging to the Group1 subgroup of the remorin gene family using the iTRAQ protein spectrum combined with virus-induced virus silencing and CRISPR/Cas9 system. Studies have shown that NbREM1 inhibits intercellular movement of RSV by regulating the size of the intercellular wire aperture.
Using protein quantitative mass spectrometry, NbREM1 was found to have significantly lower levels of protein in the early stages of viral infection, while there was no significant difference between transcription levels and control, indicating that RSV infection may affect Remorin's post-translation modification process. Bio-chemical analysis showed that the NbREM1 protein can be modified by palmylization, and NbREM1 protein 206th cysteine is its only palmylization modification point. The palmylization modification mutants of NbREM1 are trapped in the endosome and cytostytes of plants and induce cell autophagy to mediate the degradation of remorin protein, thus eliminating the negative regulation of remorin's movement between RSV cells, speeding up the movement of viruses between cells, and indicating that palmylation modification plays an important role in cell membrane positioning, protein stability, and inhibition of viral cell movement.
study found that RSV infection can interfere with the palmylation modification of the Remorin protein. In-depth studies have shown that RSV-coded motion protein NSvc4 can bind to the Remorin C-end palmylization modification bit area, interfere with its palmylization modification, resulting in Remorin cell membrane positioning weakened and mass aggregation in the endosome network, inducing cell autophagy and degradation (see figure). RSV infestion leads to the degradation of Remorin, which facilitates the rapid cell-to-cell movement of the virus to open the intercellular wire.study selected two natural hosts of RSV, single leaf host rice and gemine leaf host Ben's smoke, respectively, identified the remorin protein corresponding to the two host plants, and found that RSV used similar means to interfere with Remorin's palmylation modification and degrade the protein through autophagy, reducing its inhibition of movement between viral cells. This study reveals a new strategy for RSV to inhibit host defense that evolved in the game with the host. (Source: Science Network Li Chen)