Glycosylation and S-palmitoylation regulate SARS-CoV-2 spike protein intracellular trafficking

Chih-Feng Tien; Wan-Ting Tsai; Chun Hwa Chen; Hui-Ju Chou; Mingzi M Zhang; Jhe-Jhih Lin; En-Ju Lin; Shih-Syong Dai; Yueh-Hsin Ping; Chia-Yi Yu; Yi-Ping Kuo; Wei-Hsiang Tsai; Hsin-Wei Chen; Guann-Yi Yu

doi:10.1016/j.isci.2022.104709

Glycosylation and S-palmitoylation regulate SARS-CoV-2 spike protein intracellular trafficking

iScience. 2022 Aug 19;25(8):104709. doi: 10.1016/j.isci.2022.104709. Epub 2022 Jul 3.

Authors

Affiliations

¹ National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Taiwan.
² Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan, Taiwan.
³ Department and Institute of Pharmacology, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan.
⁴ Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan.
⁵ Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.

Abstract

Post-translational modifications (PTMs), such as glycosylation and palmitoylation, are critical to protein folding, stability, intracellular trafficking, and function. Understanding regulation of PTMs of SARS-CoV-2 spike (S) protein could help the therapeutic drug design. Herein, the VSV vector was used to produce SARS-CoV-2 S pseudoviruses to examine the roles of the ⁶¹¹LYQD⁶¹⁴ and cysteine-rich motifs in S protein maturation and virus infectivity. Our results show that ⁶¹¹LY⁶¹² mutation alters S protein intracellular trafficking and reduces cell surface expression level. It also changes S protein glycosylation pattern and decreases pseudovirus infectivity. The S protein contains four cysteine-rich clusters with clusters I and II as the main palmitoylation sites. Mutations of clusters I and II disrupt S protein trafficking from ER-to-Golgi, suppress pseudovirus production, and reduce spike-mediated membrane fusion activity. Taken together, glycosylation and palmitoylation orchestrate the S protein maturation processing and are critical for S protein-mediated membrane fusion and infection.

Keywords: Biochemistry; Cell biology; Virology.