All plasmids encoding Zaire ebolavirus (strain Mayinga) viral proteins (pCAGGS NP, VP35, VP30 and L), pCAGGS T7 polymerase, EBOV minigenome p4cis-vRNA-RLuc (encoding Renilla luciferase, VP40, GP, and VP24), and pCAGGS firefly luciferase are stored in our lab and have been described previously [21 ,22 (link)]. Plasmids expressing HA-tagged NP, VP35, VP40, GP, VP30, and VP24 (Zaire ebolavirus) were constructed previously and maintained in our lab. RBM4 cDNA was reverse transcribed from the total RNA of HEK293T cells, and was further cloned into pCAGGS-vector carrying FLAG tag by ClonExpress II kit (Vazyme, C112) according to the manufacturer’s instructions. Plasmids containing different RBM4 subdomains were further constructed with the corresponding primers (Supplementary Table 1). Sequences of all the plasmid constructs were confirmed by DNA sequencing.