An intracellular receptor expressed in many cell types that seem to have an important role in the recognition and control of virus infection is reported online this week in Nature Immunology.
Giulio Superti-Furga and colleagues find that a protein called IFIT1 is very strongly upregulated in virus-infected cells, where it then binds the 5′ end of viral RNA. They discover that IFIT1 demonstrates an exquisite ability to distinguish between host and viral RNA, which vary in their end structures, and that once bound, IFIT1 forms a large complex with many other cellular proteins and can block viral replication. As a result, mice lacking the IFIT1 protein are much more susceptible to infection by certain viruses.
The team concludes that IFIT1 is therefore a key component of a cell’s virus-recognition and virus-neutralization machinery.