Specific interaction between hnRNP H and HPV16 L1 proteins: Implications for late gene auto-regulation enabling rapid viral capsid protein production
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, Fujian 361005 (China)
Highlights: ► The RNA-binding hnRNP H regulates late viral gene expression. ► hnRNP H activity was inhibited by a late viral protein. ► Specific interaction between HPV L1 and hnRNP H was demonstrated. ► Co-localization of HPV L1 and hnRNP H inside cells was observed. ► Viral capsid protein production, enabling rapid capsid assembly, was implicated. -- Abstract: Heterogeneous nuclear ribonucleoproteins (hnRNPs), including hnRNP H, are RNA-binding proteins that function as splicing factors and are involved in downstream gene regulation. hnRNP H, which binds to G triplet regions in RNA, has been shown to play an important role in regulating the staged expression of late proteins in viral systems. Here, we report that the specific association between hnRNP H and a late viral capsid protein, human papillomavirus (HPV) L1 protein, leads to the suppressed function of hnRNP H in the presence of the L1 protein. The direct interaction between the L1 protein and hnRNP H was demonstrated by complex formation in solution and intracellularly using a variety of biochemical and immunochemical methods, including peptide mapping, specific co-immunoprecipitation and confocal fluorescence microscopy. These results support a working hypothesis that a late viral protein HPV16 L1, which is down regulated by hnRNP H early in the viral life cycle may provide an auto-regulatory positive feedback loop that allows the rapid production of HPV capsid proteins through suppression of the function of hnRNP H at the late stage of the viral life cycle. In this positive feedback loop, the late viral gene products that were down regulated earlier themselves disable their suppressors, and this feedback mechanism could facilitate the rapid production of capsid proteins, allowing staged and efficient viral capsid assembly.
- OSTI ID:
- 22224313
- Journal Information:
- Biochemical and Biophysical Research Communications, Vol. 430, Issue 3; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
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