Inhibition of HIV-1 replication by elF3f

Viruses often use host machinery in unusual ways to execute different steps during their replication. To identify host factors critical for virus replication, we screened cDNA expression libraries for genes or gene fragments that could interfere with HIV-1 vector transduction. The DNA clone that most potently inhibited HIV-1 expression encoded the N-terminal 91 aa of the eukaryotic initiation factor 3 subunit f (N91-elF3f). Overexpression of N91-elF3f or full-length elF3f drastically restricted HIV-1 replication by reducing nuclear and cytoplasmic viral mRNA levels. N91-elF3f and elF3f specifically targeted the 3' long terminal repeat (3'LTR) region in the viral mRNA. We show that the 3' end cleavage of HIV-1 mRNA precursors is specifically reduced in N91-elF3f expressing cells. Our results suggest a role of elF3f in mRNA maturation and that it can specifically interfere with the 3' end processing of HIV-1 mRNAs. cDNA genetic screen | HIV-1 restriction | RNA maturation | translation factor