Professor Guangxia Gao and his colleagues published their work recently on PNAS. The title of the paper is "p72 DEAD box RNA helicase is required for optimal function of the zinc-finger antiviral protein".

The zinc-finger antiviral protein (ZAP) is a host factor Professor Gao and his colleagues cloned, which specifically inhibits the replication of many viruses by preventing accumulation of viral mRNAs in the cytoplasm. Their previous studies revealed that ZAP directly binds to the viral mRNAs and recruits the RNA exosome to degrade the target RNA. In the present study, they identified the p72 DEAD box RNA helicase as a ZAP-interacting protein. Depletion of p72 by RNA interference reduced ZAP's activity, whereas overexpression of the full-length p72 enhanced ZAP's activity. They concluded that p72 is required for the optimal activity of ZAP and propose that p72 helps to restructure the ZAP-bound target mRNA for efficient degradation.

Mechanistic studies of ZAP might help to develop novel antiviral therapeutics, and should also help to better understand the mechanisms by which the stabilities of RNAs are regulated.

This work was supported by grants from the National Natural Science Foundation of China and the Ministry of Science and Technology (973 Program) of China.