Rice yellow stunt virus p3 protein enters the nucleus of leafhopper cell and localizes to viroplasm through interaction with N protein via importin α3-mediated pathway

Abstract Rice yellow stunt virus (RYSV) P3 protein functions as a movement protein during viral infection of a plant host; its function in insect hosts remains unclear. In this study, we investigated the subcellular localization of P3 using leafhopper ( Nephotettix cincticeps ) cell cultures. Our results showed that P3 translocated from the cytoplasm to the nucleus in RYSV-infected leafhopper cells, where it interacted with the viral N protein as a constituent of viroplasms. Interfering with the P3 gene expression significantly suppressed viral infection in N. cincticeps . Finally, we demonstrate that the nuclear translocation of P3 in leafhopper cells depended on its interaction with RYSV N protein, which enters the nucleus via an interaction with importin α3. These findings unveil a previously unknown role for P3 in RYSV infection of the insect vector and provide valuable insights into the infection dynamics of plant rhabdoviruses.