The complex co-translational processing of glycoprotein GP5 of type 1 porcine reproductive and respiratory syndrome virus
| Autor: | Susanne Kaufer, Bastian Thaa, Bernadett Peibst, Eberhard Krause, Hans Nauwynck, Sara A. Neumann, Michael Veit |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Signal peptide Cancer Research Glycosylation Swine Amino Acid Motifs Porcine Reproductive and Respiratory Syndrome Biology Protein Sorting Signals Signal peptide processing Epitope 03 medical and health sciences chemistry.chemical_compound N-linked glycosylation Viral Envelope Proteins Virology Animals Porcine respiratory and reproductive syndrome virus chemistry.chemical_classification Signal peptidase Porcine reproductive and respiratory syndrome virus biology.organism_classification Molecular biology 030104 developmental biology Infectious Diseases chemistry Glycoprotein Protein Modification Translational |
| Zdroj: | Virus research. 240 |
| ISSN: | 1872-7492 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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