Core protein of pestiviruses is processed at the C terminus by signal peptide peptidase.
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.
Heimann
Manuela
M
Institut für Virologie, FB Veterinärmedizin, Justus Liebig Universität Giessen, Frankfurter Str. 107, D-35392 Giessen, Germany.
Roman-Sosa
Gleyder
G
Martoglio
Bruno
B
Thiel
Heinz-Jürgen
HJ
Rümenapf
Till
T
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*
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