Extended stability of cyclin D1 contributes to limited cell cycle arrest at G1-phase in BHK-21 cells with Japanese encephalitis virus persistent infection

Abstract

There is increasing evidence that many RNA viruses manipulate cell cycle control to achieve favorable cellular environments for their efficient replication during infection. Although virus-induced G0/G1 arrest often delays early apoptosis temporarily, a prolonged replication of the infected virus leads host cells to eventual death. In contrast, most mammalian cells with RNA virus persistent infection often escape cytolysis in the presence of productive viral replication. In this study, we demonstrated that the extended endurance of cyclin D1 was clearly associated with the suppression of glycogen synthase kinase-3ß (GSK-3ß) expression in BHK-21 cells that are persistently infected with Japanese encephalitis virus (JEV). The G0/G1 arrest of these cells turned much loose compared to the normal BHK-21 cells with JEV acute infection. After cycloheximide treatment, cyclin D1 in the persistently infected cells lasted several hours longer than those in acutely infected cells. Furthermore, both p21(Cip1) and p27(Kip1), positive regulators for cyclin D1 accumulation in the nucleus, were suppressed in their expression, which contrasts with those in JEV acute infection. Inhibition of the GSK-3ß by lithium chloride treatment rescued a significant number of cells from cytolysis in JEV acute infection, which coincided with the levels of cyclin D1 that escaped from proteolysis. Therefore, the limitation of G1/S arrest in the BHK-21 cells with JEV persistent infection is associated with the suppression of GSK-3ß expression, resulting in the extended duration of cyclin D1.

Breaking Bad: How Viruses Subvert the Cell Cycle

“…Acute Japanese encephalitis virus (JEV) infection leads to cell cycle G0/G1 arrest with elevated p21 WAF1/CIP1 and p27 KIP1 levels, and reduced production of cyclin D (Das and Basu, 2008 ). However, in the case of persistent JEV infection, expression of these CKIs and GSK-3β, which mediates the degradation of cyclin D, is suppressed (Diehl et al, 1998 ; Kim et al, 2015 ). Thus, by extending the stability of cyclin D, persistent JEV infection bypasses cell cycle arrest, striking a balance between the persistence of lytic RNA virus and host survival.…”

Human Kinase/Phosphatase-Wide RNAi Screening Identified Checkpoint Kinase 2 as a Cellular Factor Facilitating Japanese Encephalitis Virus Infection

“…Knockdown of ATM or CHK2 suppresses RNA replication of HCV (Ariumi et al, 2008 ), and HCV NS3-NS4A interacts with ATM, whereas HCV NS5B interacts with both ATM and CHK2 (Lai et al, 2008 ). JEV is able to manipulate the cell cycle, which reduces the proliferation of neural progenitor cells (Das and Basu, 2008 ) and allows for persistent infection (Kim et al, 2015 ). JEV is also able to manipulate the cell cycle, which reduces the proliferation of neural progenitor cells (Das and Basu, 2008 ) and allows for persistent infection (Kim et al, 2015 ).…”

“…JEV is able to manipulate the cell cycle, which reduces the proliferation of neural progenitor cells (Das and Basu, 2008 ) and allows for persistent infection (Kim et al, 2015 ). JEV is also able to manipulate the cell cycle, which reduces the proliferation of neural progenitor cells (Das and Basu, 2008 ) and allows for persistent infection (Kim et al, 2015 ).…”

Rab5 and Rab11 Are Required for Clathrin-Dependent Endocytosis of Japanese Encephalitis Virus in BHK-21 Cells

“…Semliki Forest virus and type C footand-mouth disease virus enter BHK-21 cells by clathrin-dependent endocytosis (16,17). Persistent JEV infection has been demonstrated in BHK-21 cells, and numerous studies on JEV have been conducted in BHK-21 cells (18)(19)(20)(21); however, the precise entry mechanism for JEV internalization into BHK-21 cells remains unclear.…”