Mapping of Domains on the Human Parainfluenza Type 2 Virus P and NP Proteins That Are Involved in the Interaction with the L Protein

Eleven monoclonal antibodies (MAbs) directed against the large (L) protein of human parainfluenza type 2 virus (hPIV-2) were prepared to examine the interactions of the L protein with other viral proteins. Coimmunoprecipitation assays using these MAbs revealed that the L protein directly interacted with the phospho- (P) and nucleocapsid (NP) proteins in vivo and in vitro. Mutational analysis of the P or NP protein was performed to identify the region(s) on these proteins interacting with L protein, indicating that amino acids 278–353 on the P protein and amino acids 403–494 on the NP protein are essential for the binding to the L protein.