MYH9 Aggregation Induced by Direct Interaction With PRRSV GP5 Ectodomain Facilitates Viral Internalization by Permissive Cells

Abstract

Prevention and control of infection by porcine reproductive and respiratory syndrome virus (PRRSV) remains a challenge, due to our limited understanding of the PRRSV invasion mechanism. Our previous study has shown that PRRSV glycoprotein GP5 interacts with MYH9 C-terminal domain protein (PRA). Here we defined that the first ectodomain of GP5 (GP5-ecto-1) directly interacted with PRA and this interaction triggered PRA and endogenous MYH9 to form filament assembly. More importantly, MYH9 filament assembly was also formed in GP5-ecto-1-transfected MARC-145 cells. Notably, PRRSV infection of MARC-145 cells and porcine alveolar macrophages also induced endogenous MYH9 aggregation and polymerization that were required for subsequent PRRSV internalization. Moreover, overexpression of S100A4, a MYH9-specific disassembly inducer, in MARC-145 cells significantly resulted in diminished MYH9 aggregation and marked inhibition of subsequent virion internalization and infection by both PRRSV-1 and PRRSV-2 isolates. The collective results of this work reveal a novel molecular mechanism employed by MYH9 that helps PRRSV gain entry into permissive cells.

Small molecules block the interaction between porcine reproductive and respiratory syndrome virus and CD163 receptor and the infection of pig cells

“…Nevertheless, GP5 constitutes an indispensable part of the viral envelope, which may be critical for PRRSV replication in infected cells [ 20 ]. Recently it was also shown that GP5 interacts with non-muscle myosin-heavy chain 9, which is important for PRRSV infection through viral internalization mechanism [ 43 ]. Previous studies have revealed that CD163 mediates PRRSV uncoating instead of internalization for productive viral infection [ 36 – 38 ].…”

MYH9 Key Amino Acid Residues Identified by the Anti-Idiotypic Antibody to Porcine Reproductive and Respiratory Syndrome Virus Glycoprotein 5 Involve in the Virus Internalization by Porcine Alveolar Macrophages

“…Further analysis demonstrated that direct interaction between CD163 N-terminal domain and MYH9 C-terminal PRA domain contributes to PRRSV internalization by permissive cells [14]. Moreover, our latest research also indicated that the PRRSV-GP5 ectodomain interacts with MYH9 to induce MYH9 aggregation [15], a key process allowing myosin filament assembly and acquisition of motor activity [16,17], which facilitates entry of larger virus particles by bending internal and external membranes to enable internalization [18][19][20]. Therefore, it appears that MYH9 serves as a key host factor during PRRSV internalization into host cells [14,21,22].…”

“…As a cytoplasmic protein, it is known that MYH9 can relocate to the cell membrane and bind to viruses that utilize MYH9 as a receptor, such as HSV-1, EBV, and SFTSV [31,32]. Moreover, our previous study also demonstrated the direct interaction between PRRSV-GP5 and MYH9 induce aggregation of MYH9 to facilitate internalization of PRRSV virions [15]. Therefore, we wonder if interrupting the interaction between GP5 and MYH9 is capable to block internalization of PRRSV virions.…”

Recent Advances in PRRS Virus Receptors and the Targeting of Receptor–Ligand for Control

“…MYH9 is a motor protein involved in cell migration, adhesion, and morphogenesis [61]. The ectodomain of PRRSV GP5 interacts with the C-terminal domain of MYH9 during virus binding [34,62]. The ectodomain of GP5 induces aggregation of MYH9 and facilitates viral internalization in both MARC-145 cells and PAMs [62].…”

“…The ectodomain of PRRSV GP5 interacts with the C-terminal domain of MYH9 during virus binding [34,62]. The ectodomain of GP5 induces aggregation of MYH9 and facilitates viral internalization in both MARC-145 cells and PAMs [62]. Further studies showed that the amino acids E1670, K1673, E1679, and I1683 in the MYH9 C-terminal domain are the key binding residues, and a point mutation in E1670 in PAMs causes reduced permissiveness for PRRSV infection [63].…”