A central region in the hepatitis C virus NS4A protein allows formation of an active NS3-NS4A serine proteinase complex in vivo and in vitro
- PMID: 7769699
- PMCID: PMC189178
- DOI: 10.1128/JVI.69.7.4373-4380.1995
A central region in the hepatitis C virus NS4A protein allows formation of an active NS3-NS4A serine proteinase complex in vivo and in vitro
Abstract
A virus-encoded serine proteinase mediates four site-specific cleavages in the hepatitis C virus polyprotein. In addition to the catalytic domain, which is located in the N-terminal one-third of nonstructural protein NS3, the 54-residue NS4A protein is required for cleavage at some but not all sites. Here, we provide evidence for a non-ionic detergent-stable interaction between NS4A and the NS3 serine proteinase domain and demonstrate that the central region of NS4A plays a key role in NS4A-dependent processing. Hydrophobic residues, in particular Ile-29, were shown to be important for NS4A activity, and a synthetic peptide, spanning NS4A residues 22 to 34, could substitute for intact NS4A in a cell-free trans cleavage assay. Furthermore, NS4A mutations, which abolished or inhibited processing, correlated with destabilization of the NS3-NS4A complex. These results suggest that a stable interaction exists between the central region of NS4A and the NS3 catalytic domain which is required for NS4A-dependent processing. Since NS4A is required for processing at certain serine proteinase-dependent cleavage sites, this interaction may represent a new target for development of antiviral compounds.
Similar articles
-
Enhancement of hepatitis C virus NS3 proteinase activity by association with NS4A-specific synthetic peptides: identification of sequence and critical residues of NS4A for the cofactor activity.Virology. 1996 Nov 15;225(2):328-38. doi: 10.1006/viro.1996.0607. Virology. 1996. PMID: 8918919
-
Complex formation between the NS3 serine-type proteinase of the hepatitis C virus and NS4A and its importance for polyprotein maturation.J Virol. 1995 Dec;69(12):7519-28. doi: 10.1128/JVI.69.12.7519-7528.1995. J Virol. 1995. PMID: 7494258 Free PMC article.
-
The N-terminal region of hepatitis C virus nonstructural protein 3 (NS3) is essential for stable complex formation with NS4A.J Virol. 1995 Jul;69(7):4255-60. doi: 10.1128/JVI.69.7.4255-4260.1995. J Virol. 1995. PMID: 7769685 Free PMC article.
-
The hepatitis C virus NS3 proteinase: structure and function of a zinc-containing serine proteinase.Antivir Ther. 1998;3(Suppl 3):99-109. Antivir Ther. 1998. PMID: 10726060 Review.
-
Processing pathways of the hepatitis C virus proteins.J Hepatol. 1996;24(2 Suppl):11-9. J Hepatol. 1996. PMID: 8836884 Review.
Cited by
-
The C terminus of hepatitis C virus NS4A encodes an electrostatic switch that regulates NS5A hyperphosphorylation and viral replication.J Virol. 2007 Sep;81(17):8905-18. doi: 10.1128/JVI.00937-07. Epub 2007 Jun 20. J Virol. 2007. PMID: 17581983 Free PMC article.
-
Viral and cellular determinants of hepatitis C virus RNA replication in cell culture.J Virol. 2003 Mar;77(5):3007-19. doi: 10.1128/jvi.77.5.3007-3019.2003. J Virol. 2003. PMID: 12584326 Free PMC article.
-
Activity of purified hepatitis C virus protease NS3 on peptide substrates.J Virol. 1996 Oct;70(10):6694-700. doi: 10.1128/JVI.70.10.6694-6700.1996. J Virol. 1996. PMID: 8794305 Free PMC article.
-
The hepatitis C virus NS3 serine proteinase and NS4A cofactor: establishment of a cell-free trans-processing assay.Proc Natl Acad Sci U S A. 1995 Aug 15;92(17):7622-6. doi: 10.1073/pnas.92.17.7622. Proc Natl Acad Sci U S A. 1995. PMID: 7644466 Free PMC article.
-
Synthetic bulky NS4A peptide variants bind to and inhibit HCV NS3 protease.J Adv Res. 2020 Jan 3;24:251-259. doi: 10.1016/j.jare.2020.01.003. eCollection 2020 Jul. J Adv Res. 2020. PMID: 32373358 Free PMC article.
References
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Other Literature Sources
Molecular Biology Databases