Identifizierung und Charakterisierung der vom Phosphoproteingen des Newcastle Disease Virus kodierten akzessorischen Proteine W und V Like other members of the Paramyxoviridae NDV enlarges its coding capacity by differential editing of transcripts. Due to co transcriptional mRNA editing the phosphoprotein gene encodes the phospho (P) V and W protein. The three proteins share a common N terminus but specify C termini differing in length and amino acid composition. Whereas the expression and incorporation into NDV particles has been demonstrated for NDV P and V proteins evidence for the existence of a W protein was lacking. W specific antipeptide sera were generated to analyze expression of the NDV W protein based on peptides located in the unique C terminal W protein amino acid sequence that encompassed predicted antigenic sites. The corresponding rabbit sera enabled the detection of plasmid expressed W protein as well as W protein expression during infection by indirect immunofluorescence and Western blot analyses. Incorporation of W protein into viral particles was indicated by Western blot and mass spectrometric analyses. In contrast W protein was absent in infected cells and viral particles of newly generated recombinant NDV lacking W protein expression. Absence of W protein expression was achived by two different mutational approaches. Confocal microscopic analyses revealed a nuclear accumulation of W protein of NDV in infected cells attributed to a bipartite nuclear localization sequence within its unique C terminal part. Functionality of the NLS was confirmed by mutation of the two basic ... Geflügel Newcastle Krankheit akzessorische Proteine IFN Antagonist V Protein W Protein mRNA Editierung