Visualizing Tomato Spotted Wilt Virus Protein Localization: Cross-Kingdom Comparisons of Protein-Protein Interactions

Area of Science:

• Plant pathology
• Virology
• Molecular biology

Background:

• Tomato spotted wilt virus (TSWV) is a significant plant pathogen.
• Understanding TSWV protein localization and interactions is key to controlling its infection cycle.
• Orthotospoviruses utilize complex mechanisms for host-plant and insect-vector interactions.

Purpose of the Study:

• To compare the subcellular localization of TSWV proteins in plant and insect cells.
• To investigate the dynamic changes in TSWV protein localization during active plant infection.
• To identify interactions among TSWV proteins.

Main Methods:

• Comparative analysis of TSWV protein localization in plant and insect cells.
• Time-course localization studies during active plant infection using red fluorescent protein (RFP) as a nuclear/cytoplasmic marker.
• Bimolecular fluorescence complementation (BiFC) and membrane-based yeast two-hybrid (MbY2H) assays to detect protein-protein interactions.

Main Results:

• TSWV protein localization was largely consistent between plant and insect cells.
• Viral proteins lacking signal peptides and transmembrane domains (N, NSs, NSm) showed altered localization over time in plant cells during infection.
• Voids in the cytoplasm, potentially replication sites, were observed during infection, surrounded by viral proteins.
• Self-interactions were detected for NSm, N, G_N, G_C, and NSs.
• Interactions between different TSWV proteins (e.g., NSs-G_C, N-G_C) were identified.

Conclusions:

• TSWV employs similar protein localization mechanisms in both plant and insect cells.
• Dynamic protein relocalization in plant cells during infection is crucial for TSWV replication and morphogenesis.
• Identified protein-protein interactions highlight their roles in TSWV replication and assembly processes.
• This study enhances understanding of TSWV infection dynamics and host-virus interplay.