The nuclear export of cellular mRNAs is mediated by factors interacting with both the messenger ribonucleoprotein (mRNP) and the nucleoporins (Nup) to deliver the mRNAs through the nuclear pore complex to the cytoplasm.
Several viruses interfere with host mRNA nucleo-cytoplasmic trafficking, eventually leading to shutoff of host proteins expression. This gives viruses transcripts a competitive edge for access to the cellular translation machinery. Preventing the expression of host proteins is also a strategy to counteract the antiviral response.
For example, VSV matrix protein inhibits mRNA export by forming a complex with the mRNA export factor Rae1, whereas the 2A protease of picornaviruses promotes cleavage of host Nup98, Nup153, Nup62 .
Viruses inhibiting host mRNA nuclear export:
|Family||Virus||Viral protein||mRNA nuclear export inhibition strategy||references|
|Picornaviridae||Poliovirus (Enterovirus)||2A protease||Breakdown of Nup62, Nup98, Nup153|
|HRV2, HRV14, HRV16 (Enterovirus)||2A protease||Breakdown of Nup62, Nup98, Nup153|
|HRV (Enterovirus)||3A protease||Breakdown of Nup153, Nup214, and Nup358|
|Theiler's virus (Cardiovirus)||Leader protein||Hyperphosphorylation of Nup98|
|Encephalomyocarditis virus (Cardiovirus)||Leader protein||Hyperphosphorylation of Nup62, Nup153, and Nup214|
|Rhabdoviridae||Vesicular stomatitis virus (Vesiculovirus)||M protein||Disrupts Rae1-Nup98 interaction|