Fig. 6: CCND3 targets the viral NP protein independently of RNA, interfering with the RNP machinery-driven reporter activities.

a HEK293 cells mock-infected or infected with SFTSV were harvested at 24 hpi for co-immunoprecipitation (Co-IP) and WB analysis of the WCL input and IP products. b HEK293T cells were co-transfected with the Flag-CCND3 and SFTSV-NP expression plasmids or control vector, followed by Flag-pulldown and WB analysis. c Cells were treated as in (b), but the cell lysates were first subjected to UltraNuclease treatment or left untreated, followed by Flag-pulldown and WB analysis, similarly. d–f The dose-dependent inhibitory effect of CCND3 on SFTSV EGFP-based minigenome RNP reporter system. BHK-21 cells were co-transfected with the SFTSV L and NP expression plasmids and the minigenome reporter plasmid (MUTR-EGFP), along with various amounts of the CCND3 expression plasmid for 48 h, followed by fixation and high-content imaging (d) and counting (e). EGFP-positive cell ratios were normalized to the control without CCND3 overexpression (e). In a parallel experiment, the samples were also subjected to WB analysis of the EGFP expression levels (f). g The dose-dependent inhibitory effect of CCND3 on SFTSV firefly luciferase (Fluc)-based minigenome RNP reporter. The SFTSV NP and L expression plasmids and Fluc-based SFTSV minigenome reporter plasmid (MUTR-LUC) were co-transfected together with indicated amounts of the CCND3 expression plasmid and pRL-TK expressing Renilla luciferase (Rluc). Relative luciferase activities (Fluc/Rluc) were calculated and shown. Data in (a–d and f) are representative from three independent replicates with similar results. Data in (e and g) are means ± SD, n = 3 biological replicates. One-way ANOVA (e and g): *p < 0.05, ****p < 0.0001. Source data are provided as a Source Data file.