TY - JOUR
T1 - Effects of mutation in hepatitis C virus nonstructural protein 5A on interferon resistance mediated by inhibition of PKR kinase activity in mammalian cells
AU - Noguchi, Tohru
AU - Satoh, Shinya
AU - Noshi, Takeshi
AU - Hatada, Eriko
AU - Fukuda, Ryuji
AU - Kawai, Akihiko
AU - Ikeda, Satoru
AU - Hijikata, Makoto
AU - Shimotohno, Kunitada
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2001
Y1 - 2001
N2 - The IFN-induced double-stranded RNA (dsRNA)-activated protein kinase PKR is one of the key molecules in the antiviral effects of IFN. To clarify the effects of hepatitis C virus nonstructural protein 5A (NS5A) on antiviral activity of IFN, in particular on PKR kinase activity, in mammalian cells, we established inducible NS5A-expressing cell lines derived from human osteosarcoma (Saos-2). The cells expressing NS5A derived from an IFN-resistant clone (NS5A-1b) that interacted with endogenous PKR in vitro, showed a suppressive effect on IFN function as determined by interference with vesicular stomatitis virus (VSV) infection, whereas NS5A (NS5A-2a) from an IFN-sensitive clone did not block the antiviral effect of IFN. A mutant with deletion of the IFN sensitivity determining region (ISDR) in NS5A-1b (NS5A-ΔISDR) also interacted with PKR and suppressed its activity in vitro. However, neither NS5A-2a nor the C-terminal truncated mutant of NS5A-1b (NS5A-ΔC) blocked PKR activity. These observations confirmed the previous report that the inhibitory effect of NS5A on IFN activity is mediated at least in part by the repression of PKR. In addition, we showed that IFN sensitivity was determined not only by the ISDR but that the involvement of the C-terminal region of NS5A-1b is important for the suppression of PKR activity.
AB - The IFN-induced double-stranded RNA (dsRNA)-activated protein kinase PKR is one of the key molecules in the antiviral effects of IFN. To clarify the effects of hepatitis C virus nonstructural protein 5A (NS5A) on antiviral activity of IFN, in particular on PKR kinase activity, in mammalian cells, we established inducible NS5A-expressing cell lines derived from human osteosarcoma (Saos-2). The cells expressing NS5A derived from an IFN-resistant clone (NS5A-1b) that interacted with endogenous PKR in vitro, showed a suppressive effect on IFN function as determined by interference with vesicular stomatitis virus (VSV) infection, whereas NS5A (NS5A-2a) from an IFN-sensitive clone did not block the antiviral effect of IFN. A mutant with deletion of the IFN sensitivity determining region (ISDR) in NS5A-1b (NS5A-ΔISDR) also interacted with PKR and suppressed its activity in vitro. However, neither NS5A-2a nor the C-terminal truncated mutant of NS5A-1b (NS5A-ΔC) blocked PKR activity. These observations confirmed the previous report that the inhibitory effect of NS5A on IFN activity is mediated at least in part by the repression of PKR. In addition, we showed that IFN sensitivity was determined not only by the ISDR but that the involvement of the C-terminal region of NS5A-1b is important for the suppression of PKR activity.
KW - Hepatitis C virus
KW - Interferon (IFN)
KW - NS5A
KW - PKR
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U2 - 10.1111/j.1348-0421.2001.tb01322.x
DO - 10.1111/j.1348-0421.2001.tb01322.x
M3 - Article
C2 - 11838900
AN - SCOPUS:0035661068
VL - 45
SP - 829
EP - 840
JO - Microbiology and Immunology
JF - Microbiology and Immunology
SN - 0385-5600
IS - 12
ER -