A double attack by the SARS virus on host cell protein synthesis is shown in a study published online this week in Nature Structural & Molecular Biology. An understanding of such host targeting mechanisms may ultimately lead to therapeutic approaches to treat SARS.
Translation is the decoding of messenger RNAs to yield a protein, carried out by the ribosome. Many viruses interfere with the host cell's normal translation system, often requisitioning the host's own machinery for viral protein production. The SARS coronavirus protein nsp1 is known to be able to utilize such mechanisms to suppress production of host cell proteins.
Shinji Makino and colleagues now show that nsp1 modifies both host messages intended for translation and also the ribosome itself. This indicates that SARS uses a two-pronged approach to attack host translation.