Extended Data Fig. 2: CIM-834 blocks coronavirus particle formation.

a, Setup of the time-of-drug-addition assay (TOA). b,c, Ten hr p.i. intracellular vRNA b, and infectious viral particles c, were quantified (mean ± s.d., n = 3 biologically independent experiments, one-way ANOVA followed by Dunnett’s multiple comparisons with the DMSO control). d, TOA assay using VeroE6-H2B-mCherry cells and rSARS-CoV-2-mNeonGreen. e, Quantification of %infected cells (mNeonGreen⁺ and mCherry⁺ VeroE6 cells) relative to the DMSO control (mean ± s.d., n = 6 biologically independent experiments). f, Virus kinetics experiment with the same setup (compounds added at 0 h p.i.) and quantification of infected cells at different time points. In a-f, hydroxychloroquine was tested at 10 µM, CIM-834 and nirmatrelvir at 1 µM. g, CIM-834 does not influence the co-localization of M and TGN46, a marker for the trans-Golgi network. Data (mean ± s.d.) from two independent experiments. h, TEM (top) and tomographic reconstruction (bottom) of cytoplasmic regions of DMSO- or CIM-834(1 µM)-treated SARS-CoV-2 infected cells (10 h p.i.). a1, a2, Details of boxed regions highlighted in Fig. 4g, showing additional examples of assembly sites located both at the center of the DMV cluster and at its periphery, in proximity of the terminal region of Golgi cisternae (G). m, mitochondrion. b1, b2: Magnified regions from Fig. 4g, showing concentric stacks of membranes (orange dashed lines) detected in CIM-834 treated cells and their proximity to DMVs (*). c1,c2: Slices from tomographic acquisition of DMSO (c1) and CIM-834-treated cells (c2), highlighting the regions magnified respectively below (d, f) or in Fig. 4h (c, e). Section thickness: 70 nm (a1,a2,b1,b2). Tomographic section thickness: 0.78 nm (c1,c2). i, Inhibition of the activities of purified, recombinant enzymes assayed in vitro in the presence of CIM-834 and appropriate reference compounds.