MEK1-ERKs signal cascade is required for the replication of Enterovirus 71 (EV71)

► We observed in vitro infection with EV71 induced a biphasic activation of ERK. ► Inhibition of ERK activation and knockdown of MEK1 clearly impaired virus production. ► By contrast, silencing MEK2 expression did not such effect. ► Both MEK isoforms were activated and translocated to nucleus upon EV71 infection. ► We conclude that only MEK1-ERKs activation is necessary for the virus production.