8
Function
Plays a role in modulating the host immune response (PubMed:31986261, PubMed:35343786, PubMed:36689483). May act as a secreted virokine by mimicking interleukin-17A (IL17A), and thereby binding to the IL17RA receptor, leading to activation of the IL17 pathway and increased secretion of pro-inflammatory factors (PubMed:35343786, PubMed:36689483). Contributes to the cytokine storm during SARS-CoV-2 infection when secreted by unconventional pathway (PubMed:33723527, PubMed:36689483). May act by down-regulating major histocompability complex class I (MHC-I) at cell surface (PubMed:34021074, PubMed:35157849). May inhibit expression of some members of the IFN-stimulated gene (ISG) family including hosts IGF2BP1/ZBP1, MX1 and MX2, and DHX58 (PubMed:34177923).
Post-translational modifications
Glycosylated by the host when secreted via the conventional pathway. The glycosylated form cannot bind IL17A and would not participate in the cytokine storm.
Cellular localization
- Secreted
- Is secreted during a normal viral infection by unconventional pathway (PubMed:35157849, PubMed:36689483). Its mRNA is expressed in cytoplasm and not spliced during a viral infection, but is spliced when expressed from cDNA in nucleus (PubMed:35157849). Splicing changes localization to host endosome and/or cytoplasm (PubMed:33060197, PubMed:34177923). May also localize in nucleus when fused with GFP (PubMed:34177923).
Alternative names
ORF8 protein, ORF8, Non-structural protein 8, ns8, 8