A viral suppressor protein inhibits host RNA silencing by hooking up with Argonautes.
RNA viruses are particularly vulnerable to RNAi-based defenses in the host, and thus have evolved specific proteins, known as viral suppressors of RNA silencing (VSRs), as a counterdefense. In this issue of Genes & Development, Azevedo and colleagues (pp. 904-915) discovered that P38, the VSR of Turnip crinkle virus, uses its glycine/tryptophane (GW) motifs as an ARGONAUTE (AGO) hook to attract and disarm the host's essential effector of RNA silencing. Several GW motif-containing cellular proteins are known to be important partners of AGOs in RNA silencing effector complexes in yeast, plants, and animals. The GW motif appears to be a versatile and effective tool for regulating the activities of RNA silencing pathways, and the use of GW mimicry to compete for and inhibit host AGOs may be a strategy used by many pathogens to counteract host RNAi-based defenses.
Jin
Hailing
H
Institute for Integrative Genome Biology, University of California at Riverside, Riverside, California 92521, USA.
Zhu
Jian-Kang
JK
D036022:Capsid Proteins / Q000378:metabolism*; D019184:Carmovirus / Q000378:metabolism*; D054884:Host-Pathogen Interactions; D010944:Plants / Q000276:immunology / Q000821:virology*; D034622:RNA Interference
D036022:Capsid Proteins