The present study showed that the nuclear re-localization
of 3CD and 3C0 could be induced by 2Apro alone. It is
reported that 3CD and 3C0 of poliovirus have nuclear localization
signal, which only functions under poliovirus infection
[4]. Previously studies have indicated that NPCs were
altered during poliovirus infection [15,26] and this could
not be simply explained as virus-induced leakiness of the
NE because some functions of cellular NPCs remained
[26]. The degradation of Nup98, Nup153, and p62 by
2Apro has also been reported as important for poliovirus
infection [26,27]. It is likely that NPCs are altered by 2Apro
and then induce the re-localization of 3CD and 3C0 to the
cell nucleus. A variety of nucleo-cytoplasmic trafficking
pathways are inhibited in poliovirus-infected cells such as
importin a/b and transportin, which are the targets of the
SV40 large T antigen and heterogeneous nuclear ribonucleoprotein,
respectively. However, the transportation of
some other proteins that use the transportin-serine/
arginine-rich (SR) pathway, such as the SR protein SC35,
is not affected by poliovirus infection [26]. The
re-localization of 3CD and 3C0
, therefore, may be involved
in a special cytoplasmic–nucleic pathway that is induced
during poliovirus infection or 2Apro expression. Further
studies should be dedicated to determine the pathway used
by poliovirus 3CD and 3C0 to enter the nucleus.
Poliovirus 2Apro can cleave the eIF4G directly or
indirectly and suppress the cap-dependent translation
[28,29]. To overexpress Nup153-mCherry during investi