Deubiquitinase ubiquitin-specific protease 3 (USP3) inhibits HIV-1 replication via promoting APOBEC3G (A3G) expression in both enzyme activity-dependent and -independent manners

Abstract

Background:Ubiquitination plays an essential role in many biological processes, including viral infection, and can be reversed by deubiquitinating enzymes (DUBs). Although some studies discovered that DUBs inhibit or enhance viral infection by various mechanisms, there is lack of information on the role of DUBs in virus regulation, which needs to be further investigated.Methods:Immunoblotting, real-time polymerase chain reaction, in vivo/in vitro deubiquitination, protein immunoprecipitation, immunofluorescence, and co-localization biological techniques were employed to examine the effect of ubiquitin-specific protease 3 (USP3) on APOBEC3G (A3G) stability and human immunodeficiency virus (HIV) replication. To analyse the relationship between USP3 and HIV disease progression, we recruited 20 HIV-infected patients to detect the levels of USP3 and A3G in peripheral blood and analysed their correlation with CD4+ T-cell counts. Correlation was estimated by Pearson correlation coefficients (for parametric data).Results:The results demonstrated that USP3 specifically inhibits HIV-1 replication in an A3G-dependent manner. Further investigation found that USP3 stabilized 90% to 95% of A3G expression by deubiquitinating Vif-mediated polyubiquitination and blocking its degradation in an enzyme-dependent manner. It also enhances the A3G messenger RNA (mRNA) level by binding to A3G mRNA and stabilizing it in an enzyme-independent manner. Moreover, USP3 expression was positively correlated with A3G expression (r = 0.5110) and CD4+ T-cell counts (r = 0.5083) in HIV-1-infected patients.Conclusions:USP3 restricts HIV-1 viral infections by increasing the expression of the antiviral factor A3G. Therefore, USP3 may be an important target for drug development and serve as a novel therapeutic strategy against viral infections.

Ubiquitin specific peptidase 3: an emerging deubiquitinase that regulates physiology and diseases

“…But surprisingly, USP3 plays a positive role in the fight against human immunodeficiency virus (HIV). USP3 can deliver HIV-1 inhibition in two ways, either in an enzyme-dependent or enzyme-independent manner [ 34 ]. Vif is a viral accessory protein encoded by HIV that induces degradation of APOBEC3G (A3G), a host defensive factor.…”

“…At the same time, USP3 can directly stabilize A3G mRNA to increase the amount of A3G. The experiments showed a positive correlation between USP3 mRNA, A3G mRNA and the number of CD4+ T cells [ 34 ].…”

“… Diseases The role of USP3 Related molecule References Breast cancer + KLF5 Wu et al [ 64 ] Colorectal cancer − SMAD4 Wang et al [ 67 ] AR Zheng et al [ 69 ] Esophageal cancer + Aurora A Shi et al [ 62 ] Gallbladder cancer + PKLR Liang et al [ 57 ] Glioblastoma + Snail Fan et al [ 45 ] miR455-5p Chen et al [ 46 ] Smo Tu et al [ 18 ] Gastric cancer + SND1-IT1 Jin et al [ 40 ] COL9A3 COL6A5 Wu et al (2021) miR-224-5p Li et al [ 39 ] SUZ12 Wu et al [ 64 ] / Fang at al. [ 37 ] Human immunodeficiency virus-1 − A3G Zhao et al [ 34 ] Influenza A virus + miR-26a Gao et al [ 31 ] Leukemia − H2AK119ub Chae et al [ 65 ] Neuroblastoma + ALYREF Nagy et al [ 50 ] REST ...…”

USP3: Key deubiquitylation enzyme in human diseases

“…While it promotes infection through the inhibition of the type I interferon signaling pathway, 35,72 Zhao et al. presented contrasting evidence, indicating that USP3 inhibits HIV replication by enhancing the host defensive factor AG3 73 . Additionally, Zhuang et al.…”

“…presented contrasting evidence, indicating that USP3 inhibits HIV replication by enhancing the host defensive factor AG3. 73 Additionally, Zhuang et al. proposed that USP3 enhances ASC stability by eliminating the K‐48 linked ubiquitin chain.…”