Proteolytic Cleavage of the SARS-CoV-2 Spike Protein and the Role of the Novel S1/S2 Site

• Published in: iScience Vol. 23; no. 6; p. 101212
• Main Authors: Jaimes, Javier A., Millet, Jean K., Whittaker, Gary R.
• Format: Journal Article Web Resource
• Language: English
• Published: United States Elsevier Inc 26.06.2020; Elsevier BV; Elsevier
• Subjects: Biochemistry; Biochemistry, Molecular Biology; Life Sciences; Microbiology and Parasitology; Virology; Biochemistry; Virology
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2020.101212

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 19 (COVID-19) has rapidly spread to the entire world within a few months. The origin of SARS-CoV-2 has been related to the lineage B Betacoronavirus SARS-CoV and SARS-related coronaviruses found in bats. Early characterizations of the SARS-CoV-2 genome revealed the existence of a distinct four amino acid insert within the spike (S) protein (underlined, SPRRAR↓S), at the S1/S2 site located at the interface between the S1 receptor binding subunit and the S2 fusion subunit. Notably, this insert appears to be a distinguishing feature among SARS-related sequences and introduces a potential cleavage site for the protease furin. Here, we investigate the potential role of this novel S1/S2 cleavage site and present direct biochemical evidence for proteolytic processing by a variety of proteases. We discuss these findings in the context of the origin of SARS-CoV-2, viral stability, and transmission. [Display omitted] •SARS-CoV-2 spike protein harbors a distinct four amino acid insertion at the S1/S2 site•The S1/S2 site can be cleaved by furin-like, trypsin-like, and cathepsin proteases•The S1/S2 insert likely enhances spike protein cleavage by several proteases in vivo Biochemistry; Virology