NSP9 of SARS-CoV-2 attenuates nuclear transport by hampering nucleoporin 62 dynamics and functions in host cells

• Published in: Biochemical and biophysical research communications Vol. 586; pp. 137 - 142
• Main Authors: Makiyama, Kei, Hazawa, Masaharu, Kobayashi, Akiko, Lim, Keesiang, Voon, Dominic C., Wong, Richard W.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.2022; The Author(s). Published by Elsevier Inc
• Subjects: Active Transport, Cell Nucleus; COVID-19 - metabolism; COVID-19 - virology; Endoplasmic Reticulum - metabolism; Endoplasmic Reticulum - virology; Gene Knockdown Techniques; HeLa Cells; Host Microbial Interactions - physiology; Humans; Membrane Glycoproteins - antagonists & inhibitors; Membrane Glycoproteins - genetics; Membrane Glycoproteins - metabolism; Models, Biological; NSP9; Nuclear Envelope - metabolism; Nuclear Envelope - virology; Nuclear Pore Complex Proteins - antagonists & inhibitors; Nuclear Pore Complex Proteins - genetics; Nuclear Pore Complex Proteins - metabolism; Nucleoporin; NUP62; p65; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; RNA-Binding Proteins - genetics; RNA-Binding Proteins - metabolism; SARS-CoV-2; SARS-CoV-2 - metabolism; Transcription Factor RelA - metabolism; Viral Nonstructural Proteins - genetics; Viral Nonstructural Proteins - metabolism; SARS-CoV-2; NSP9; Nucleoporin; p65; NUP62
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2021.11.046

Nuclear pore complexes (NPC) regulate molecular traffics on nuclear envelope, which plays crucial roles during cell fate specification and diseases. The viral accessory protein NSP9 of SARS-CoV-2 is reported to interact with nucleoporin 62 (NUP62), a structural component of the NPC, but its biological impact on the host cell remain obscure. Here, we established new cell line models with ectopic NSP9 expression and determined the subcellular destination and biological functions of NSP9. Confocal imaging identified NSP9 to be largely localized in close proximity to the endoplasmic reticulum. In agreement with the subcellular distribution of NSP9, association of NSP9 with NUP62 was observed in cytoplasm. Furthermore, the overexpression of NSP9 correlated with a reduction of NUP62 expression on the nuclear envelope, suggesting that attenuating NUP62 expression might have contributed to defective NPC formation. Importantly, the loss of NUP62 impaired translocation of p65, a subunit of NF-κB, upon TNF-α stimulation. Concordantly, NSP9 over-expression blocked p65 nuclear transport. Taken together, these data shed light on the molecular mechanisms underlying the modulation of host cells during SARS-CoV-2 infection. •Overexpression of NSP9 of SARS-CoV-2 reduces nucleoporin 62 (NUP62) expression on the nuclear envelope.•Loss of NUP62 impaired translocation of p65, a subunit of NF–κB, upon TNF-α stimulation.•NSP9 over-expression blocked p65 nuclear transport.