title: Core protein of pestiviruses is processed at the C terminus by signal peptide peptidase.
abstract: The core protein of pestiviruses is released from the polyprotein by viral and cellular proteinases. Here we report on an additional intramembrane proteolytic step that generates the C terminus of the core protein. C-terminal processing of the core protein of classical swine fever virus (CSFV) was blocked by the inhibitor (Z-LL)(2)-ketone, which is specific for signal peptide peptidase (SPP). The same effect was obtained by overexpression of the dominant-negative SPP D(265)A mutant. The presence of (Z-LL)(2)-ketone reduced the viability of CSFV almost 100-fold in a concentration-dependent manner. Reduction of virus viability was also observed in infection experiments using a cell line that inducibly expressed SPP D(265)A. The position of SPP cleavage was determined by C-terminal sequencing of core protein purified from virions. The C terminus of CSFV core protein is alanine(255) and is located in the hydrophobic center of the signal peptide. The intramembrane generation of the C terminus of the CSFV core protein is almost identical to the processing scheme of the core protein of hepatitis C viruses.
authors.affiliation: Institut für Virologie, FB Veterinärmedizin, Justus Liebig Universität Giessen, Frankfurter Str. 107, D-35392 Giessen, Germany.
authors.forename: Manuela
authors.initials: M
authors.lastname: Heimann
authors.forename: Gleyder
authors.initials: G
authors.lastname: Roman-Sosa
authors.forename: Bruno
authors.initials: B
authors.lastname: Martoglio
authors.forename: Heinz-Jürgen
authors.initials: HJ
authors.lastname: Thiel
authors.forename: Till
authors.initials: T
authors.lastname: Rümenapf
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000378:metabolism*; D002460:Cell Line; D006692:Classical Swine Fever Virus / Q000378:metabolism*; D004151:Dipeptides / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D020539:Sequence Analysis, Protein; D013552:Swine; D014758:Viral Core Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: C415363:1, 3-di-(N-carboxybenzoyl-leucyl-leucyl)amino acetone; D004151:Dipeptides; D004791:Enzyme Inhibitors; D014758:Viral Core Proteins; D016282:Aspartic Acid Endopeptidases; C460085:signal peptide peptidase