Zhang Yaodong, Dai Jun, Tan Lei, Mu Daoe, Zhang Ziyan, Song Cuiping, Qu Yang, Tang Ning, Liao Ying, Ding Chan, Sun Yingjie, Qiu Xusheng
Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China.
Experimental Animal Center, Zunyi Medical University, Zunyi, 563000, China.
Vet Res. 2025 Jul 1;56(1):126. doi: 10.1186/s13567-025-01552-6.
As an important structural protein of Newcastle disease virus (NDV), the M protein plays a crucial role in the assembly and budding of the virus. In previous reports, we confirmed the existence of a classical nuclear export signal (NES) sequence on the M protein (i.e., amino acids 257 to 266), which plays an important role in the nuclear export of the protein. In this study, we found that the NES motif is associated with the evolutionary history of NDV, and found that the NES-mediated nuclear export efficiency of M proteins varies among different genotypes. Further research on the LaSota-NES and JSD0812-NES variants showed that the NES both affects the nuclear-cytoplasmic trafficking efficiency of M protein and influences the formation of virus-like particles (VLPs). The NES conforms to the chromosome region maintenance 1 (CRM1)-associated consensus leucine/isoleucine-rich NES motif, and our results confirm that the NES-mediated nuclear-cytoplasmic trafficking of M protein is dependent on the CRM1 pathway. At last, several recombinant LaSota strains were rescued using reverse genetics, with their NES sequence replaced by either a potent NES motif, or an R247K mutation, or both. The rescued rLaSota-QMS and rLaSota-FM strains showed elevated hemagglutination (HA) titers, increased 50% egg infective dose (EID) values, along with marginally higher mean death time (MDT) and intracerebral pathogenicity index (ICPI) values, all of which are attributable to their enhanced proliferation rates when compared to the wild-type (wt) rLaSota strain. Our findings contribute to a better understanding of the molecular mechanisms of replication and pathogenicity in NDV and, by extension, in other paramyxoviruses.
作为新城疫病毒（NDV）的一种重要结构蛋白，M蛋白在病毒的组装和出芽过程中起着关键作用。在之前的报道中，我们证实了M蛋白上存在一个经典的核输出信号（NES）序列（即氨基酸257至266），该序列在蛋白的核输出中发挥重要作用。在本研究中，我们发现NES基序与NDV的进化历史相关，并且发现不同基因型的M蛋白由NES介导的核输出效率有所不同。对LaSota-NES和JSD0812-NES变体的进一步研究表明，NES既影响M蛋白的核质运输效率，也影响病毒样颗粒（VLP）的形成。NES符合与染色体区域维持1（CRM1）相关的富含亮氨酸/异亮氨酸的NES基序共识，我们的结果证实M蛋白由NES介导的核质运输依赖于CRM1途径。最后，利用反向遗传学拯救了几种重组LaSota毒株，将其NES序列替换为一个有效的NES基序，或R247K突变，或两者都替换。拯救的rLaSota-QMS和rLaSota-FM毒株显示出血凝（HA）效价升高、50%鸡胚感染剂量（EID）值增加，同时平均死亡时间（MDT）和脑内致病指数（ICPI）值略高，所有这些都归因于与野生型（wt）rLaSota毒株相比它们增强的增殖率。我们的发现有助于更好地理解NDV以及其他副粘病毒复制和致病的分子机制。
