Cleavage and activation of the severe acute respiratory syndrome coronavirus spike protein by human airway trypsin-like protease.

Abstract

The highly pathogenic severe acute respiratory syndrome coronavirus (SARS-CoV) poses a constant threat to human health. The viral spike protein (SARS-S) mediates host cell entry and is a potential target for antiviral intervention. Activation of SARS-S by host cell proteases is essential for SARS-CoV infectivity but remains incompletely understood. Here, we analyzed the role of the type II transmembrane serine proteases (TTSPs) human airway trypsin-like protease (HAT) and transmembrane protease, serine 2 (TMPRSS2), in SARS-S activation. We found that HAT activates SARS-S in the context of surrogate systems and authentic SARS-CoV infection and is coexpressed with the viral receptor angiotensin-converting enzyme 2 (ACE2) in bronchial epithelial cells and pneumocytes. HAT cleaved SARS-S at R667, as determined by mutagenesis and mass spectrometry, and activated SARS-S for cell-cell fusion in cis and trans, while the related pulmonary protease TMPRSS2 cleaved SARS-S at multiple sites and activated SARS-S only in trans. However, TMPRSS2 but not HAT expression rendered SARS-S-driven virus-cell fusion independent of cathepsin activity, indicating that HAT and TMPRSS2 activate SARS-S differentially. Collectively, our results show that HAT cleaves and activates SARS-S and might support viral spread in patients.

• Authors: Stephanie Bertram, Ilona Glowacka, Marcel A Müller, Hayley Lavender, Kerstin Gnirss, Inga Nehlmeier, Daniela Niemeyer, Yuxian He, Graham Simmons, Christian Drosten, Elizabeth J Soilleux, Olaf Jahn, Imke Steffen, Stefan Pöhlmann
• Journal: Journal of virology (J Virol) Vol. 85 Issue 24 Pg. 13363-72 (Dec 2011) ISSN: 1098-5514 [Electronic] United States
• PMID: 21994442 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Membrane Glycoproteins
• Receptors, Virus
• Spike Glycoprotein, Coronavirus
• Viral Envelope Proteins
• Peptidyl-Dipeptidase A
• ACE2 protein, human
• Angiotensin-Converting Enzyme 2
• Serine Endopeptidases
• human airway trypsin-like protease

Topics

• Angiotensin-Converting Enzyme 2
• Cell Line
• Gene Expression
• Host-Pathogen Interactions
• Humans
• Membrane Glycoproteins (metabolism)
• Peptidyl-Dipeptidase A (biosynthesis)
• Proteolysis
• Receptors, Virus (biosynthesis)
• Severe acute respiratory syndrome-related coronavirus (pathogenicity)
• Serine Endopeptidases (metabolism)
• Spike Glycoprotein, Coronavirus
• Viral Envelope Proteins (metabolism)