TY - JOUR
T1 - The α isoform of protein kinase CKI is responsible for hepatitis C virus NS5A hyperphosphorylation
AU - Quintavalle, Manuela
AU - Sambucini, Sonia
AU - Di Pietro, Chiara
AU - De Francesco, Raffaele
AU - Neddermann, Petra
PY - 2006/11
Y1 - 2006/11
N2 - Hepatitis C virus (HCV) has been the subject of intensive studies for nearly two decades. Nevertheless, some aspects of the virus life cycle are still a mystery. The HCV nonstructural protein 5A (NS5A) has been shown to be a modulator of cellular processes possibly required for the establishment of viral persistence. NS5A is heavily phosphorylated, and a switch between a basally phosphorylated form of NS5A (p56) and a hyperphosphorylated form of NS5A (p58) seems to play a pivotal role in regulating HCV replication. Using kinase inhibitors that specifically inhibit the formation of NS5A-p58 in cells, we identified the CKI kinase family as a target. NS5A-p58 increased upon overexpression of CKI-α, CKI-δ, and CKI-ε, whereas the RNA interference of only CKI-α reduced NS5A hyperphosphorylation. Rescue of inhibition of NS5A-p58 was achieved by CKI-α overexpression, and we demonstrated that the CKI-α isoform is targeted by NS5A hyperphosphorylation inhibitors in living cells. Finally, we showed that down-regulation of CKI-α attenuates HCV RNA replication.
AB - Hepatitis C virus (HCV) has been the subject of intensive studies for nearly two decades. Nevertheless, some aspects of the virus life cycle are still a mystery. The HCV nonstructural protein 5A (NS5A) has been shown to be a modulator of cellular processes possibly required for the establishment of viral persistence. NS5A is heavily phosphorylated, and a switch between a basally phosphorylated form of NS5A (p56) and a hyperphosphorylated form of NS5A (p58) seems to play a pivotal role in regulating HCV replication. Using kinase inhibitors that specifically inhibit the formation of NS5A-p58 in cells, we identified the CKI kinase family as a target. NS5A-p58 increased upon overexpression of CKI-α, CKI-δ, and CKI-ε, whereas the RNA interference of only CKI-α reduced NS5A hyperphosphorylation. Rescue of inhibition of NS5A-p58 was achieved by CKI-α overexpression, and we demonstrated that the CKI-α isoform is targeted by NS5A hyperphosphorylation inhibitors in living cells. Finally, we showed that down-regulation of CKI-α attenuates HCV RNA replication.
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U2 - 10.1128/JVI.01465-06
DO - 10.1128/JVI.01465-06
M3 - Article
C2 - 16943283
AN - SCOPUS:33750737787
VL - 80
SP - 11305
EP - 11312
JO - Journal of Virology
JF - Journal of Virology
SN - 0022-538X
IS - 22
ER -