Rice black streaked dwarf virus P7-2 forms a SCF complex through binding to Oryza sativa SKP1-like proteins, and interacts with GID2 involved in the gibberellin pathway

Abstract

As a core subunit of the SCF complex that promotes protein degradation through the 26S proteasome, S-phase kinase-associated protein 1 (SKP1) plays important roles in multiple cellular processes in eukaryotes, including gibberellin (GA), jasmonate, ethylene, auxin and light responses. P7-2 encoded by Rice black streaked dwarf virus (RBSDV), a devastating viral pathogen that causes severe symptoms in infected plants, interacts with SKP1 from different plants. However, whether RBSDV P7-2 forms a SCF complex and targets host proteins is poorly understood. In this study, we conducted yeast two-hybrid assays to further explore the interactions between P7-2 and 25 type I Oryza sativa SKP1-like (OSK) proteins, and found that P7-2 interacted with eight OSK members with different binding affinity. Co-immunoprecipitation assay further confirmed the interaction of P7-2 with OSK1, OSK5 and OSK20. It was also shown that P7-2, together with OSK1 and O. sativa Cullin-1, was able to form the SCF complex. Moreover, yeast two-hybrid assays revealed that P7-2 interacted with gibberellin insensitive dwarf2 (GID2) from rice and maize plants, which is essential for regulating the GA signaling pathway. It was further demonstrated that the N-terminal region of P7-2 was necessary for the interaction with GID2. Overall, these results indicated that P7-2 functioned as a component of the SCF complex in rice, and interaction of P7-2 with GID2 implied possible roles of the GA signaling pathway during RBSDV infection.

Abscisic acid negatively modulates plant defence against rice black‐streaked dwarf virus infection by suppressing the jasmonate pathway and regulating reactive oxygen species levels in rice

“…Sun, Zhang, et al, ). S7‐2 encodes a component of the SCF (Skp, Cullin, F‐box) complex (Tao et al, ). Segments S8 and S10 encode a core capsid protein and an outer capsid protein (Liu, Wei, Zhong, & Li, ; Liu, Wei, Zhong, & Li, ; Z.…”

“…S7-1 encodes a tubular protein and is localized in the PD of plant cells (Isogai, Uyeda, & Lee, 1998;. S7-2 encodes a component of the SCF (Skp, Cullin, F-box) complex (Tao et al, 2017).…”

Comparative proteomic analysis of maize (Zea mays L.) seedlings under rice black-streaked dwarf virus infection

“…Another protein of RBSDV, P7–2, functions as a key subunit of Skp1/Cul1/F-box complex ubiquitin ligase by interacting with SKP1 [ 7 ]. In rice and maize, the P7–2 protein is also involved in gibberellin pathway by interacting with GID2 during the RBSDV infection [ 8 ]. P9–1 of RSBSDV is an alpha-helical protein that plays important roles in the early phase of virus life cycle by forming intracellular viroplasms [ 9 ].…”

Rice black‐streaked dwarf virus‐encoded P5‐1 regulates the ubiquitination activity of SCF E3 ligases and inhibits jasmonate signaling to benefit its infection in rice

“…Although interactions between viral factors and CRL components have been reported previously for DNA and RNA viruses (Zhang et al, 2001;Oh et al, 2006;Lozano-Duran et al, 2011;Fu et al, 2012), it is not clear whether CSN complexes can interact with RBSDV-encoded factor(s). A previous report by Tao et al (2017) showed that the RBSDV P7-2 protein functioned as an SCF complex component in rice. The authors suggested that the gibberellin signaling pathway might play a role in RBSDV infection in rice .…”