Abstract: Objective As SARS-CoV-2 spreads around the world，an in-depth study of virus-host interaction is essential for exploring SARS-CoV-2 pathogenesis. MethodsThe SRAS-CoV-2 nonstructural protein Nsp1-Nsp16 was cloned by PCR and homologous recombination assay into a eukaryotic expression vector，and Nsp1-Nsp16 protein expression was detected by Western blot. Then，the influence of Nsp2 exerted on total ubiquitin levels was determined by Western blot，and the distribution of Nsp2 in the cells was found by immunofluorescence. Finally，co-immunoprecipitation was used to detect the interaction between Nsp2 and ubiquitin. ResultsWestern blot analysis revealed that Nsp1-Nsp16 could express smoothly in A549 cells. Meanwhile，it was shown that Nsp2 increased total ubiquitin expression in the cytoplasm. Co-immunoprecipitation experiments results declared that Nsp2 could interact with ubiquitin protein. ConclusionWe successfully construct the expression vector of nonstructural protein Nsp1-Nsp16，and find that Nsp2 can increase the total ubiquitin level of cells and be ubiquitinated. This study demonstrates that Nsp2 is involved in the interaction between SARS-CoV-2 and host via the ubiquitin pathway，which lays a foundation for further research on the mechanism of SARS-CoV-2 and host.

Key words: SARS-CoV-2, nonstructural proteins, Nsp2, ubiquitin