Severe acute respiratory syndrome coronavirus replication is severely impaired by MG132 due to proteasome-independent inhibition of M-calpain.
J. Virol. 86, 10112-10122 (2012)
The ubiquitin-proteasome system (UPS) is involved in the replication of a broad range of viruses. Since replication of the murine hepatitis virus (MHV) is impaired upon proteasomal inhibition, the relevance of the UPS for the replication of the severe acute respiratory syndrome coronavirus (SARS-CoV) was investigated in this study. We demonstrate that the proteasomal inhibitor MG132 strongly inhibits SARS-CoV replication by interfering with early steps of the viral life cycle. Surprisingly, other proteasomal inhibitors (e.g., lactacystin and bortezomib) only marginally affected viral replication, indicating that the effect of MG132 is independent of proteasomal impairment. Induction of autophagy by MG132 treatment was excluded from playing a role, and no changes in SARS-CoV titers were observed during infection of wild-type or autophagy-deficient ATG5(-/-) mouse embryonic fibroblasts overexpressing the human SARS-CoV receptor, angiotensin-converting enzyme 2 (ACE2). Since MG132 also inhibits the cysteine protease m-calpain, we addressed the role of calpains in the early SARS-CoV life cycle using calpain inhibitors III (MDL28170) and VI (SJA6017). In fact, m-calpain inhibition with MDL28170 resulted in an even more pronounced inhibition of SARS-CoV replication (>7 orders of magnitude) than did MG132. Additional m-calpain knockdown experiments confirmed the dependence of SARS-CoV replication on the activity of the cysteine protease m-calpain. Taken together, we provide strong experimental evidence that SARS-CoV has unique replication requirements which are independent of functional UPS or autophagy pathways compared to other coronaviruses. Additionally, this work highlights an important role for m-calpain during early steps of the SARS-CoV life cycle.
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Publikationstyp
Artikel: Journalartikel
Dokumenttyp
Wissenschaftlicher Artikel
Typ der Hochschulschrift
Herausgeber
Schlagwörter
ENDOPLASMIC-RETICULUM STRESS; PAPAIN-LIKE PROTEASE; SARS-CORONAVIRUS; VIRUS ENTRY; NUCLEOCAPSID PROTEIN; DEPENDENT ENTRY; SPIKE PROTEIN; CATHEPSIN-L; HOST-CELLS; SYSTEM
Keywords plus
Sprache
englisch
Veröffentlichungsjahr
2012
Prepublished im Jahr
HGF-Berichtsjahr
2012
ISSN (print) / ISBN
0022-538X
e-ISSN
1098-5514
ISBN
Bandtitel
Konferenztitel
Konferzenzdatum
Konferenzort
Konferenzband
Quellenangaben
Band: 86,
Heft: 18,
Seiten: 10112-10122
Artikelnummer: ,
Supplement: ,
Reihe
Verlag
American Society for Microbiology (ASM)
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Tag d. mündl. Prüfung
0000-00-00
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Prüfer
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0000-00-00
Anmelder/Inhaber
weitere Inhaber
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Priorität
Begutachtungsstatus
Peer reviewed
POF Topic(s)
30203 - Molecular Targets and Therapies
Forschungsfeld(er)
Immune Response and Infection
PSP-Element(e)
G-502700-003
Förderungen
Copyright
Erfassungsdatum
2012-10-26