Heat-shock protein 90α is involved in maintaining the stability of VP16 and VP16-mediated transactivation of α genes from herpes simplex virus-1.
Mol Med 2018;
24:65. [PMID:
30577726 PMCID:
PMC6303900 DOI:
10.1186/s10020-018-0066-x]
[Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 12/05/2018] [Indexed: 01/24/2023] Open
Abstract
Background
Numerous host cellular factors are exploited by viruses to facilitate infection. Our previous studies and those of others have shown heat-shock protein 90 (Hsp90), a cellular molecular chaperone, is involved in herpes simplex virus (HSV)-1 infection. However, the function of the dominant Hsp90 isoform and the relationship between Hsp90 and HSV-1 α genes remain unclear.
Methods and results
Hsp90α knockdown or inhibition significantly inhibited the promoter activity of HSV-1 α genes and downregulated virion protein 16(VP16) expression from virus and plasmids. The Hsp90α knockdown-induced suppression of α genes promoter activity and downregulation of α genes was reversed by VP16 overexpression, indicating that Hsp90α is involved in VP16-mediated transcription of HSV-1 α genes. Co-immunoprecipitation experiments indicated that VP16 interacted with Hsp90α through the conserved core domain within VP16. Based on using autophagy inhibitors and the presence of Hsp90 inhibitors in ATG7−/− (autophagy-deficient) cells, Hsp90 inhibition-induced degradation of VP16 is dependent on macroautophagy-mediated degradation but not chaperone-mediated autophagy (CMA) pathway. In vivo studies demonstrated that treatment with gels containing Hsp90 inhibitor effectively reduced the level of VP16 and α genes, which may contribute to the amelioration of the skin lesions in an HSV-1 infection mediated zosteriform model.
Conclusion
Our study provides new insights into the mechanisms by which Hsp90α facilitates the transactivation of HSV-1 α genes and viral infection, and highlights the importance of developing selective inhibitors targeting the interaction between Hsp90α and VP16 to reduce toxicity, a major challenge in the clinical use of Hsp90 inhibitors.
Electronic supplementary material
The online version of this article (10.1186/s10020-018-0066-x) contains supplementary material, which is available to authorized users.
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