The Orf9b Protein of SARS-CoV-2 Modulates Mitochondrial Protein Biogenesis

Overview

Journal J Cell Biol

Specialty Cell Biology

Date 2023 Sep 8

PMID 37682539

Authors

Svenja Lenhard

Sarah Gerlich

Azkia Khan

Saskia Rodl

Jan-Eric Bokenkamp

Esra Peker

Christine Zarges

Janina Faust

Zuzana Storchova

Markus Raschle

Jan Riemer

Johannes M Herrmann

Affiliations

Soon will be listed here.

Abstract

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) expresses high amounts of the protein Orf9b to target the mitochondrial outer membrane protein Tom70. Tom70 serves as an import receptor for mitochondrial precursors and, independently of this function, is critical for the cellular antiviral response. Previous studies suggested that Orf9b interferes with Tom70-mediated antiviral signaling, but its implication for mitochondrial biogenesis is unknown. In this study, we expressed Orf9b in human HEK293 cells and observed an Orf9b-mediated depletion of mitochondrial proteins, particularly in respiring cells. To exclude that the observed depletion was caused by the antiviral response, we generated a yeast system in which the function of human Tom70 could be recapitulated. Upon expression of Orf9b in these cells, we again observed a specific decline of a subset of mitochondrial proteins and a general reduction of mitochondrial volume. Thus, the SARS-CoV-2 virus is able to modulate the mitochondrial proteome by a direct effect of Orf9b on mitochondrial Tom70-dependent protein import.

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References

Weidberg H, Amon A . MitoCPR-A surveillance pathway that protects mitochondria in response to protein import stress. Science. 2018; 360(6385). PMC: 6528467. DOI: 10.1126/science.aan4146. View

Ballman K, Grill D, Oberg A, Therneau T . Faster cyclic loess: normalizing RNA arrays via linear models. Bioinformatics. 2004; 20(16):2778-86. DOI: 10.1093/bioinformatics/bth327. View

Chang X, Ismail N, Rahman A, Xu D, Chan R, Ong S . Long COVID-19 and the Heart: Is Cardiac Mitochondria the Missing Link?. Antioxid Redox Signal. 2022; 38(7-9):599-618. PMC: 10025846. DOI: 10.1089/ars.2022.0126. View

Stukalov A, Girault V, Grass V, Karayel O, Bergant V, Urban C . Multilevel proteomics reveals host perturbations by SARS-CoV-2 and SARS-CoV. Nature. 2021; 594(7862):246-252. DOI: 10.1038/s41586-021-03493-4. View

Tyanova S, Temu T, Cox J . The MaxQuant computational platform for mass spectrometry-based shotgun proteomics. Nat Protoc. 2016; 11(12):2301-2319. DOI: 10.1038/nprot.2016.136. View

McWhirter S, tenOever B, Maniatis T . Connecting mitochondria and innate immunity. Cell. 2005; 122(5):645-7. DOI: 10.1016/j.cell.2005.08.026. View

Li J, Cui W, Sha B . The structural plasticity of Tom71 for mitochondrial precursor translocations. Acta Crystallogr Sect F Struct Biol Cryst Commun. 2010; 66(Pt 9):985-9. PMC: 2935211. DOI: 10.1107/S1744309110025522. View

Suzuki H, Maeda M, Mihara K . Characterization of rat TOM70 as a receptor of the preprotein translocase of the mitochondrial outer membrane. J Cell Sci. 2002; 115(Pt 9):1895-905. DOI: 10.1242/jcs.115.9.1895. View

Kee J, Thudium S, Renner D, Glastad K, Palozola K, Zhang Z . SARS-CoV-2 disrupts host epigenetic regulation via histone mimicry. Nature. 2022; 610(7931):381-388. PMC: 9533993. DOI: 10.1038/s41586-022-05282-z. View

10.

Liu Q, Chang C, Wooldredge A, Fong B, Kennedy B, Zhou C . Tom70-based transcriptional regulation of mitochondrial biogenesis and aging. Elife. 2022; 11. PMC: 8926401. DOI: 10.7554/eLife.75658. View

11.

Hossain A, Akter S, Rashid A, Khair S, Rubayet Ul Alam A . Unique mutations in SARS-CoV-2 Omicron subvariants' non-spike proteins: Potential impacts on viral pathogenesis and host immune evasion. Microb Pathog. 2022; 170:105699. PMC: 9356572. DOI: 10.1016/j.micpath.2022.105699. View

12.

Goldmacher V, Bartle L, Skaletskaya A, Dionne C, Kedersha N, Vater C . A cytomegalovirus-encoded mitochondria-localized inhibitor of apoptosis structurally unrelated to Bcl-2. Proc Natl Acad Sci U S A. 1999; 96(22):12536-41. PMC: 22976. DOI: 10.1073/pnas.96.22.12536. View

13.

Thorne L, Bouhaddou M, Reuschl A, Zuliani-Alvarez L, Polacco B, Pelin A . Evolution of enhanced innate immune evasion by SARS-CoV-2. Nature. 2021; 602(7897):487-495. PMC: 8850198. DOI: 10.1038/s41586-021-04352-y. View

14.

Chan N, Likic V, Waller R, Mulhern T, Lithgow T . The C-terminal TPR domain of Tom70 defines a family of mitochondrial protein import receptors found only in animals and fungi. J Mol Biol. 2006; 358(4):1010-22. DOI: 10.1016/j.jmb.2006.02.062. View

15.

Martensson C, Priesnitz C, Song J, Ellenrieder L, Doan K, Boos F . Mitochondrial protein translocation-associated degradation. Nature. 2019; 569(7758):679-683. DOI: 10.1038/s41586-019-1227-y. View

16.

Miserey-Lenkei S, Trajkovic K, DAmbrosio J, Patel A, copic A, Mathur P . A comprehensive library of fluorescent constructs of SARS-CoV-2 proteins and their initial characterisation in different cell types. Biol Cell. 2021; 113(7):311-328. PMC: 8014678. DOI: 10.1111/boc.202000158. View

17.

Brandherm L, Kobas A, Klohn M, Bruggemann Y, Pfaender S, Rassow J . Phosphorylation of SARS-CoV-2 Orf9b Regulates Its Targeting to Two Binding Sites in TOM70 and Recruitment of Hsp90. Int J Mol Sci. 2021; 22(17). PMC: 8430508. DOI: 10.3390/ijms22179233. View

18.

Schlenstedt G, Hurt E, Doye V, Silver P . Reconstitution of nuclear protein transport with semi-intact yeast cells. J Cell Biol. 1993; 123(4):785-98. PMC: 2200159. DOI: 10.1083/jcb.123.4.785. View

19.

Bottinger L, Gornicka A, Czerwik T, Bragoszewski P, Loniewska-Lwowska A, Schulze-Specking A . In vivo evidence for cooperation of Mia40 and Erv1 in the oxidation of mitochondrial proteins. Mol Biol Cell. 2012; 23(20):3957-69. PMC: 3469512. DOI: 10.1091/mbc.E12-05-0358. View

20.

Gao X, Zhu K, Qin B, Olieric V, Wang M, Cui S . Crystal structure of SARS-CoV-2 Orf9b in complex with human TOM70 suggests unusual virus-host interactions. Nat Commun. 2021; 12(1):2843. PMC: 8121815. DOI: 10.1038/s41467-021-23118-8. View