PT - JOURNAL ARTICLE AU - Alba Escalera AU - Ana S. Gonzalez-Reiche AU - Sadaf Aslam AU - Ignacio Mena AU - Rebecca L. Pearl AU - Manon Laporte AU - Andrea Fossati AU - Raveen Rathnasinghe AU - Hala Alshammary AU - Adriana van de Guchte AU - Mehdi Bouhaddou AU - Thomas Kehrer AU - Lorena Zuliani-Alvarez AU - David A. Meekins AU - Velmurugan Balaraman AU - Chester McDowell AU - Jürgen A. Richt AU - Goran Bajic AU - Emilia Mia Sordillo AU - Nevan Krogan AU - Viviana Simon AU - Randy A. Albrecht AU - Harm van Bakel AU - Adolfo Garcia-Sastre AU - Teresa Aydillo TI - SARS-CoV-2 variants of concern have acquired mutations associated with an increased spike cleavage AID - 10.1101/2021.08.05.455290 DP - 2021 Jan 01 TA - bioRxiv PG - 2021.08.05.455290 4099 - http://biorxiv.org/content/early/2021/08/05/2021.08.05.455290.short 4100 - http://biorxiv.org/content/early/2021/08/05/2021.08.05.455290.full AB - For efficient cell entry and membrane fusion, SARS-CoV-2 spike (S) protein needs to be cleaved at two different sites, S1/S2 and S2’ by different cellular proteases such as furin and TMPRSS2. Polymorphisms in the S protein can affect cleavage, viral transmission, and pathogenesis. Here, we investigated the role of arising S polymorphisms in vitro and in vivo to understand the emergence of SARS-CoV-2 variants. First, we showed that the S:655Y is selected after in vivo replication in the mink model. This mutation is present in the Gamma Variant Of Concern (VOC) but it also occurred sporadically in early SARS-CoV-2 human isolates. To better understand the impact of this polymorphism, we analyzed the in vitro properties of a panel of SARS-CoV-2 isolates containing S:655Y in different lineage backgrounds. Results demonstrated that this mutation enhances viral replication and spike protein cleavage. Viral competition experiments using hamsters infected with WA1 and WA1-655Y isolates showed that the variant with 655Y became dominant in both direct infected and direct contact animals. Finally, we investigated the cleavage efficiency and fusogenic properties of the spike protein of selected VOCs containing different mutations in their spike proteins. Results showed that all VOCs have evolved to acquire an increased spike cleavage and fusogenic capacity despite having different sets of mutations in the S protein. Our study demonstrates that the S:655Y is an important adaptative mutation that increases viral cell entry, transmission, and host susceptibility. Moreover, SARS-COV-2 VOCs showed a convergent evolution that promotes the S protein processing.Competing Interest StatementThe A.G.-S. laboratory has received research support from Pfizer, Senhwa Biosciences, Kenall Manufacturing, Avimex, Johnson & Johnson, Dynavax, 7Hills Pharma, N-fold LLC, Pharmamar, ImmunityBio, Accurius, Nanocomposix, Hexamer and Merck, outside of the reported work. A.G.-S. has consulting agreements for the following companies involving cash and/or stock: Vivaldi Biosciences, Contrafect, 7Hills Pharma, Avimex, Vaxalto, Pagoda, Accurius, Esperovax, Farmak, Applied Biological Laboratories and Pfizer, outside of the reported work. A.G.-S. is inventor on patents and patent applications on the use of antivirals and vaccines for the treatment and prevention of virus infections, owned by the Icahn School of Medicine at Mount Sinai, New York. The Icahn School of Medicine at Mount Sinai has filed a patent application relating to SARS-CoV-2 serological assays, which lists Viviana Simon as co-inventor. Mount Sinai has spun out a company, Kantaro, to market serological tests for SARS-CoV-2.