Full-length complementary DNA of hepatitis C virus genome from an infectious blood sample

Aizaki, Hideki; Aoki, Yasunori; Harada, Takashi; Ishii, Koji; Suzuki, Tetsuro; Nagamori, Seishi; Toda, Gotaro; Matsuura, Yoshiharu; Miyamura, Tatsuo

doi:10.1002/hep.510270242

Cited by 60 publications

(38 citation statements)

References 59 publications

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“…These results indicate that HCV core protein amino acids 44 to 71 have a function in both PA28␥ binding and nuclear retention. To further confirm this observation, we examined embryonic fibroblasts derived from PA28␥ knockout mice (2) (Fig. 7B).…”

Section: Mapping Of the Pa28␥-binding Region Of The Hcv Core Proteinmentioning

confidence: 73%

Proteasome Activator PA28γ-Dependent Nuclear Retention and Degradation of Hepatitis C Virus Core Protein

Moriishi

Okabayashi

Nakai

et al. 2003

J Virol

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142

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Hepatitis C virus (HCV) core protein plays an important role in the formation of the viral nucleocapsid and a regulatory protein involved in hepatocarcinogenesis. In this study, we have identified proteasome activator PA28␥ (11S regulator ␥) as an HCV core binding protein by using yeast two-hybrid system. This interaction was demonstrated not only in cell culture but also in the livers of HCV core transgenic mice. These findings are extended to human HCV infection by the observation of this interaction in liver specimens from a patient with chronic HCV infection. Neither the interaction of HCV core protein with other PA28 subtypes nor that of PA28␥ with other Flavivirus core proteins was detected. Deletion of the PA28␥-binding region from the HCV core protein or knockout of the PA28␥ gene led to the export of the HCV core protein from the nucleus to the cytoplasm. Overexpression of PA28␥ enhanced the proteolysis of the HCV core protein. Thus, the nuclear retention and stability of the HCV core protein is regulated via a PA28␥-dependent pathway through which HCV pathogenesis may be exerted.Hepatitis C virus (HCV) is the causative agent in most cases of acute and chronic non-A, non-B hepatitis (16, 51). Over 50% of patients with acute infection evolve into a chronic carrier state (26), and persistent infection frequently results in chronic hepatitis. Chronic HCV infection may lead to the development of cirrhosis and eventually hepatocellular carcinoma (21, 51). HCV belongs to the Flaviviridae family, a family that also includes Japanese encephalitis virus (JEV) and Dengue fever virus (DEN), and possesses a viral genome consisting of a single positive-strand RNA of approximately 9.6 kb and encoding approximately 3,000 amino acids in a single polypeptide (9, 58). HCV proteins are produced as a single polypeptide that is posttranslationally cleaved by host cellular peptidases and viral proteases to yield at least 10 viral proteins (7,10,12,54).A comparison of the genome structure of HCV with other flaviviruses, as well as the observation of a specific interaction of viral sense RNA with HCV core protein in cells (53, 68), suggests that the HCV core protein forms the nucleocapsid with viral genome RNA. An HCV core protein consisting of the N-terminal 191 amino acids is generated by protein cleavage by host signal peptidase(s) (37, 52). The HCV core protein is further processed into a mature core protein lacking its C-terminal hydrophobic region by either an unknown host protease (52, 65) or by a signal peptide peptidase (36). The matured core protein is retained on the endoplasmic reticulum (ER) either by an interaction with immature core protein on the ER membrane (29) or via E1 envelope protein (32). The C-terminal hydrophobic region between amino acids 174 and 191 is essential for HCV core protein anchoring on the ER membrane and for the signal sequence of E1 protein to translocate into the ER lumen. Core proteins truncated at the C termini are mainly localized in the nucleus and, to lesser extent, in the cytoplasm...

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Section: Mapping Of the Pa28␥-binding Region Of The Hcv Core Proteinmentioning

confidence: 73%

Proteasome Activator PA28γ-Dependent Nuclear Retention and Degradation of Hepatitis C Virus Core Protein

Moriishi

Okabayashi

Nakai

et al. 2003

J Virol

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142

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“…We do not confirm this finding as E2 is recognized by MAbCBH2 in the absence of E1 expression suggesting that the formation of the CBH2 epitope does not strictly depend on E1 coexpression and heterodimerization. However, it has to be noted that the E2 protein used in this study (genotype 1b; isolate NIHJ1) (44,52,53) is different from those used by Cocquerel et al (51) and that recognition by MAbCHB2 could be isolate-specific.…”

Section: Soluble E2 Binds To Dc-sign and L-sign-c-type Mannose Lectinmentioning

confidence: 76%

DC-SIGN and L-SIGN Are High Affinity Binding Receptors for Hepatitis C Virus Glycoprotein E2

Lozach

Lortat‐Jacob

Lavalette

et al. 2003

Journal of Biological Chemistry

331

285

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The hepatitis C virus (HCV) genome codes for highly mannosylated envelope proteins, which are naturally retained in the endoplasmic reticulum. We found that the HCV envelope glycoprotein E2 binds the dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) and the related liver endothelial cell lectin L-SIGN through high-mannose N-glycans. Hepatitis C virus (HCV)1 is the major causative agent of non-A, non-B hepatitis throughout the world with more than 170 million people infected (1). Contamination with infected blood by injecting drug users is the primary risk factor for acquiring HCV infection. The majority of infected patients are unable to clear the virus, and many develop chronic liver disease, cirrhosis, and hepatocellular carcinoma (2). Replication of the HCV genome could be demonstrated in vivo and in vitro in liver hepatocytes (3, 4) and hematopoietic cells including dendritic cells and B cells (5, 6). However, the molecular mechanism by which the virus targets to these sites of replication, notably in the liver, is not known.HCV is a small, enveloped, plus-strand RNA virus belonging to the family flaviviridae and genus hepacivirus. The HCV RNA genome is 9600 nucleotides in length and encodes a single polyprotein that is post-translationally cleaved into up to 10 polypeptides including three structural proteins (core, E1, and E2), located at the N terminus, and five nonstructural proteins (1,7,8). Shortly after translocation into the endoplasmic reticulum (ER), oligosaccharide transferase catalyzes addition of Glc3Man9GlcNAc2 complexes at up to 6 (E1) and 11 (E2) N-glycosylation sites (for review see Ref. 9). Glucose residues are removed by glucosidases I and II, and correctly folded proteins are released from ER chaperones calnexin and calreticulin (10 -13). The transmembrane domains of E1 and E2 are responsible for both heterodimerization (14) and retention of the glycoproteins in a high-mannose EndoH-sensitive glycoform in the ER (15)(16)(17). By analogy to other flaviviruses it is assumed that HCV capsids bud from the cytoplasm into the ER and that enveloped particles follow the secretion pathway through the Golgi. However, attempts to produce secreted HCV particles in vitro have not been successful so far (18 -20), and it is not known if E1 and E2 on mature infectious virions possess a high-mannose, complex, or mixed glycosylation.Several receptors have been proposed that could play a role in HCV entry into hepatocytes. The low density lipoprotein (LDL) receptor has been shown to mediate HCV internalization via binding to virus-associated LDL particles (21,22). A second putative HCV receptor, the tetraspanin CD81, has been identified as a high affinity binding receptor (1.8 nM) for soluble recombinant E2 from HCV genotype 1a (23, 24). CD81 and LDL receptor are expressed in most cell types and thus likely do not account for the hepatic tropism of the virus. Furthermore E2 binds to the hepatoblastoma cell line HepG2, which does not express CD81 (25). More recently tw...

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“…Human PA28␥ cDNA was isolated from a human fetal brain library (18). The gene encoding HCV core protein was amplified from HCV strain J1 (genotype 1b) (34) and cloned into pCAG-GS (35). Mouse cDNAs of RXR␣ and LXR␣ were amplified by PCR from the total cDNAs of the mouse liver.…”

Section: Methodsmentioning

confidence: 99%

Critical role of PA28γ in hepatitis C virus-associated steatogenesis and hepatocarcinogenesis

Moriishi

Mochizuki

Moriya

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

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188

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Hepatitis C virus (HCV) is a major cause of chronic liver disease that frequently leads to steatosis, cirrhosis, and eventually hepatocellular carcinoma (HCC). HCV core protein is not only a component of viral particles but also a multifunctional protein because liver steatosis and HCC are developed in HCV core gene-transgenic (CoreTg) mice. Proteasome activator PA28␥/REG␥ regulates host and viral proteins such as nuclear hormone receptors and HCV core protein. Here we show that a knockout of the PA28␥ gene induces the accumulation of HCV core protein in the nucleus of hepatocytes of CoreTg mice and disrupts development of both hepatic steatosis and HCC. Furthermore, the genes related to fatty acid biosynthesis and srebp-1c promoter activity were up-regulated by HCV core protein in the cell line and the mouse liver in a PA28␥-dependent manner. Heterodimer composed of liver X receptor ␣ (LXR␣) and retinoid X receptor ␣ (RXR␣) is known to up-regulate srebp-1c promoter activity. Our data also show that HCV core protein enhances the binding of LXR␣/RXR␣ to LXR-response element in the presence but not the absence of PA28␥. These findings suggest that PA28␥ plays a crucial role in the development of liver pathology induced by HCV infection.fatty acid ͉ proteasome ͉ sterol regulatory element-binding protein (SREBP) ͉ RXR␣ ͉ LXR␣ H epatitis C virus (HCV) belongs to the Flaviviridae family, and it possesses a positive, single-stranded RNA genome that encodes a single polyprotein composed of Ϸ3,000 aa. The HCV polyprotein is processed by host and viral proteases, resulting in 10 viral proteins. Viral structural proteins, including the capsid (core) protein and two envelope proteins, are located in the N-terminal one-third of the polyprotein, followed by nonstructural proteins.HCV infects Ͼ170 million individuals worldwide, and then it causes liver disease, including hepatic steatosis, cirrhosis, and eventually hepatocellular carcinoma (HCC) (1). The prevalence of fatty infiltration in the livers of chronic hepatitis C patients has been reported to average Ϸ50% (2, 3), which is higher than the percentage in patients infected with hepatitis B virus and other liver diseases. However, the precise functions of HCV proteins in the development of fatty liver remain unknown because of the lack of a system sufficient to investigate the pathogenesis of HCV. HCV core protein expression has been shown to induce lipid droplets in cell lines and hepatic steatosis and HCC in transgenic mice (4-6). These reports suggest that HCV core protein plays an important role in the development of various types of liver failure, including steatosis and HCC.Recent reports suggest that lipid biosynthesis affects HCV replication (7-9). Involvement of a geranylgeranylated host protein, FBL2, in HCV replication through the interaction with NS5A suggests that the cholesterol biosynthesis pathway is also important for HCV replication (9). Increases in saturated and monounsaturated fatty acids enhance HCV RNA replication, whereas increases in polyunsaturat...

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Full-length complementary DNA of hepatitis C virus genome from an infectious blood sample

Cited by 60 publications

References 59 publications

Proteasome Activator PA28γ-Dependent Nuclear Retention and Degradation of Hepatitis C Virus Core Protein

Proteasome Activator PA28γ-Dependent Nuclear Retention and Degradation of Hepatitis C Virus Core Protein

DC-SIGN and L-SIGN Are High Affinity Binding Receptors for Hepatitis C Virus Glycoprotein E2

Critical role of PA28γ in hepatitis C virus-associated steatogenesis and hepatocarcinogenesis

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