Fachbereich Veterinärmedizin



    The complex co-translational processing of glycoprotein GP5 of type 1 porcine reproductive and respiratory syndrome virus (2017)

    Zeitschriftenartikel / wissenschaftlicher Beitrag
    Thaa, Bastian
    Kaufer, Susanne (WE 5)
    Neumann, Sara A
    Peibst, Bernadett
    Nauwynck, Hans
    Krause, Eberhard
    Veit, Michael (WE 5)
    Virus research; 240 — S. 112–120
    ISSN: 0168-1702
    DOI: 10.1016/j.virusres.2017.08.004
    Pubmed: 28807563
    Institut für Virologie

    Robert-von-Ostertag-Str. 7-13
    Gebäude 35
    14163 Berlin
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    Abstract / Zusammenfassung

    GP5 and M, the major membrane proteins of porcine reproductive and respiratory syndrome virus (PRRSV), are the driving force for virus budding and a target for antibodies. We studied co-translational processing of GP5 from an European PRRSV-1 strain. Using mass spectrometry, we show that in virus particles of a Lelystad variant, the signal peptide of GP5 was absent due to cleavage between glycine-34 and asparagine-35. This cleavage site removes an epitope for a neutralizing monoclonal antibody, but leaves intact another epitope recognized by neutralizing pig sera. Upon ectopic expression of this GP5 in cells, signal peptide cleavage was however inefficient. Complete cleavage occurred when cysteine-24 was changed to proline or an unused glycosylation site involving asparagine-35 was mutated. Insertion of proline at position 24 also caused carbohydrate attachment to asparagine-35. Glycosylation sites introduced downstream of residue 35 were used, but did not inhibit signal peptide processing. Co-expression of the M protein rescued this processing defect in GP5, suggesting a novel function of M towards GP5. We speculate that a complex interplay of the co-translational modifications of GP5 affect the N-terminal structure of the mature proteins and hence its antigenicity.