The conserved QTQTX motif in the SARS-CoV-2 spike protein is dispensable for cleavage and lung cell entry of the emerging variant BA.3.2

The furin motif in the SARS-CoV-2 spike (S) protein is important for lung cell entry. It is embedded in an extended loop structure and preceded by a highly conserved QTQTX motif that is required for efficient furin cleavage of the SARS-CoV-2 WA-1 S protein. BA.3.2 is an emerging SARS-CoV-2 saltation variant that is spreading globally in April 2026 and encodes for a highly mutated S protein. Here, we analyzed whether the QTQTX motif is also required for spike protein cleavage and lung cell entry of BA.3.2. We report that two patient-derived spike sequences of the BA.3.2 subvariant BA.3.2.2 lack the first QT repeat of the QTQTX motif and show that this motif is largely dispensable for both cleavage and lung cell entry of BA.3.2.2, which we found to depend on TMPRSS2. Our results suggest that the reconfiguration of the BA.3.2 S protein during persistent infection may have significantly altered the determinants of furin cleavage.