Network based analysis of hepatitis C virus Core and NS4B protein interactions

Abstract

Hepatitis C virus (HCV) is a major cause of chronic liver disease worldwide. Here we attempt to further our understanding of the biological context of protein interactions in HCV pathogenesis, by investigating interactions between HCV proteins Core and NS4B and human host proteins. Using the yeast two-hybrid (Y2H) membrane protein system, eleven human host proteins interacting with Core and 45 interacting with NS4B were identified, most of which are novel. These interactions were used to infer overall protein interaction maps linking the viral proteins with components of the host cellular networks. Core and NS4B proteins contribute to highly compact interaction networks that may enable the virus to respond rapidly to host physiological responses to HCV infection. Analysis of the interaction networks highlighted enriched biological pathways likely influenced in HCV infection. Inspection of individual interactions offered further insights into the possible mechanisms that permit HCV to evade the host immune response and appropriate host metabolic machinery. Follow-up cellular assays with cell lines infected with HCV genotype 1b and 2a strains validated Core interacting proteins ENO1 and SLC25A5 and host protein PXN as novel regulators of HCV replication and viral production. ENO1 siRNA knockdown was found to inhibit HCV replication in both the HCV genotypes and viral RNA release in genotype 2a. PXN siRNA inhibition was observed to inhibit replication specifically in genotype 1b but not in genotype 2a, while SLC25A5 siRNA facilitated a minor increase in the viral RNA release in genotype 2a. Thus, our analysis can provide potential targets for more effective anti-HCV therapeutic intervention.

Identification of PTC725, an Orally Bioavailable Small Molecule That Selectively Targets the Hepatitis C Virus NS4B Protein

“…HCV NS4B was reported to interact with nearly all HCV proteins (30)(31)(32)(33)(34)(35)(36). Therefore, we investigated whether the NS4B inhibitors or their drug-resistant mutations interrupt the interaction of NS4B with other viral proteins.…”

“…Disruption of the GTPase or RNAbinding activity leads to impairment of HCV replication. NS4B has also been reported to interact with many HCV proteins (30)(31)(32)(33)(34)(35)(36), as well as with several cellular proteins (28,37,38). NS4B has been suggested to regulate viral protein translation (39)(40)(41).…”

Proteomic analysis of porcine alveolar macrophages infected with porcine circovirus type 2

“…We also found that cellular proteins associated with energy metabolism, including glycolytic enzymes ENO1, and key regulatory enzymes involved in amino acid transport and metabolism, such as AST and GLS, were disordered. ENO1 is involved in inflammatory responses, cell differentiation [49], viral replication and tumor progression [50,51]. Viral replication requires the coordinated production.…”

Elucidating Novel Hepatitis C Virus–Host Interactions Using Combined Mass Spectrometry and Functional Genomics Approaches

“…Thus, unraveling the hostvirus interactome is essential for novel antiviral target identification and for a better understanding of the cellular and viral biology. The majority of previous studies were done using a yeast two-hybrid system (16,17). However, this system is not optimal for membrane-bound proteins like those of HCV.…”