Disruption of spike protein N-glycosylation induces its endoplasmic reticulum retention and attenuates SARS-CoV-2 infectivity

The spike (S) protein of SARS-CoV-2 is extensively glycosylated, with N-glycosylation sites remaining highly conserved during viral evolution. While inhibiting N-glycosylation has been shown to significantly suppress SARS-CoV-2 infection, the underlying molecular mechanisms remain incompletely characterized. Here, we identify that two N-glycosylation sites, N61 and N343, are critical for spike maturation. We demonstrate that asparagine-to-aspartic acid substitutions (N to D) at these sites lead