Unique long 11 and 16 protein act as a bridge for the unique long 11, 16, 21 protein and glycoprotein E interaction in duck plague virus replication.

Unique long (UL) 11, 16, and 21 proteins are duck plague virus (DPV) tegument proteins that are important in virus replication and cell-to-cell spread. gE is an envelope glycoprotein that is critical for DPV virulence. However, information regarding the interactions among DPV viral proteins is limited. Here, we identified a classic and effective interaction among UL11, UL16, UL21 and gE in which UL111-50 aa interacts with UL16 and UL161-155 aa interacts with UL11; this interaction was not affected by the myristoylation of UL11. Further research revealed that UL16 acts as a bridge connecting UL11 and UL21 and that UL16 interacts with the C-terminus of UL21. Knockdown of UL11 by shRNA decreased the amount of UL16 and UL21 assembled in DPV. We found that UL11 promotes the interaction between UL16 and gE and that UL111-50 aa interacts with gE. Taken together, our findings reveal the interactions among these four proteins, which might provide information relevant to DPV viral and host interactions or the development of therapeutic strategies for DPV.