Post-translational modifications of coronavirus proteins: roles and function

Fung, To Sing; Liu, Ding Xiang

Interestingly, although SARS-CoV M protein is N-linked glycosylated, its accessory protein 3a is O-linked glycosylated [162] . The SARS-CoV protein 3a and M share the same N-exo/C-endo membrane topology, and both proteins contain three TM domains [163] . O-linked glycans of the SARS-CoV protein 3a were resistant to the treatment of PNGase F, and pulse-chase analysis suggested that the oligosaccharides were acquired post-translationally [162] . Protein 3a has been implicated in modulating host immune response, such as upregulating fibrinogen expression [164] and production of proinflammatory cytokines [165] . However, whether O-linked glycosylation contributes to the immune-modulating activities of SARS-CoV protein 3a is not known.