Cellular Vimentin Interacts with Foot-and-Mouth Disease Virus Nonstructural Protein 3A and Negatively Modulates Viral Replication.

Nonstructural protein 3A of foot-and-mouth disease virus (FMDV) is a partially conserved protein of 153 amino acids in most FMDVs examined to date and plays important roles in virus replication, virulence and host range. To better understand the role of 3A during FMDV infection, we used coimmunoprecipitation followed by mass spectrometry to identify host proteins that interact with 3A in FMDV infected cells. Here we report that cellular vimentin is a host binding partner for 3A. The 3A-vimentin interaction was further confirmed by coimmunoprecipitation, glutathione S-transferase (GST) pull down and immunofluorescence assays. Alanine scanning mutagenesis indicated that amino acid residues 15-21 at the N-terminal region of the FMDV 3A are responsible for the interaction between 3A and vimentin. Using reverse genetics, we demonstrate that mutations in 3A that disrupt the interaction between 3A and vimentin are also critical for virus growth. Overexpression of vimentin significantly suppressed the replication of FMDV, whereas knockdown of vimentin significantly enhanced FMDV replication. However, chemical disruption of the vimentin network by acrylamide resulted in a significant decrease in viral yield, suggesting that an intact vimentin network is needed for FMDV replication. These results indicate that vimentin interacts with FMDV 3A and negatively regulate FMDV replication, and that the vimentin-3A interaction is essential for FMDV replication. This study provides information that should be helpful for understanding the molecular mechanism of FMDV replication.IMPORTANCE FMDV non-structural protein 3A plays important roles in virus replication, host range and virulence. To further understand the role of 3A during FMDV infection, identification of host cell factors that interact with FMDV 3A is needed. Here we found that vimentin is a direct binding partner of FMDV 3A, and manipulation of vimentin has a negatively effect on virus replication. We also demonstrated that amino acid residues 15-21 at the N-terminal region of the FMDV 3A are responsible for the interaction between 3A and vimentin and the 3A-vimentin interaction is critical for the viral replication since full-length cDNA clone harboring mutations in 3A, which were disrupt 3A-vimenin reactivity, could not produce viable virus progeny. This study provides information that not only provides us a better understanding of the mechanism of FMDV replication but also helps in the development of novel antiviral strategies in the future.