Molecular characterization of the interaction between the N-terminal region of Potato virus X (PVX) coat protein (CP) and Nicotiana benthamiana PVX CP-interacting protein, NbPCIP1

• Published in: Virus genes 2013-06, Vol.46 (3), p.517-523
• Main Authors: Park, Mi-Ri, Kim, Kook-Hyung
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Biomedicine; Capsid Proteins - genetics; Capsid Proteins - metabolism; DNA Mutational Analysis; Host-Pathogen Interactions; Medical Microbiology; Nicotiana - virology; Nicotiana benthamiana; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Sciences; Potato virus X; Potexvirus - physiology; Protein Interaction Domains and Motifs; Protein Interaction Mapping; Two-Hybrid System Techniques; Virology
• ISSN: 0920-8569; 1572-994X
• DOI: 10.1007/s11262-013-0896-0

Using yeast two-hybrid assays and a Nicotiana benthamiana cDNA library, we previously identified an N. benthamiana protein, NbPCIP1, that interacts with Potato virus X (PVX) coat protein (CP). We also previously determined that NbPCIP1 enhances PVX replication in plants. To determine the domains and/or amino acid residues required for PVX CP and NbPCIP1 interaction, here we used yeast two-hybrid and β-galactosidase filter assays to test the effects of deletion and site-directed mutations on the interaction. Truncation analysis revealed that the N-terminal region of PVX CP interacts with NbPCIP1. To identify which N-terminal region PVX CP amino acid(s) interact with NbPCIP1, we substituted the 12 charged amino acids on the PVX CP N-terminal region to alanine. Yeast two-hybrid, β-galactosidase filter, and bimolecular fluorescence complementation (BiFC) assays confirmed that ten of the 12 alanine-substituted mutations blocked the interaction with NbPCIP1. The results suggest that the N-terminal region of PVX CP including its helical structure is important for interaction with NbPCIP1.