Assays for monitoring viral manipulation of host ARE-mRNA turnover.

Early host responses to viral infection rapidly induce an antiviral gene expression program that limits viral replication and recruits sentinel cells of the innate immune system. These responses are mediated by cytokines. The mRNAs that encode cytokines typically harbor destabilizing adenine- and uridine-rich elements (AREs) that direct their constitutive degradation in the cytoplasm. In response to a variety of signals, including viral infection, small pools of cytoplasmic ARE-mRNAs are rapidly stabilized and translated. Thus, mRNA stability plays a key role in antiviral gene expression. Intriguingly, recent studies have identified viral proteins that specifically target ARE-mRNAs for stabilization, suggesting that certain proteins encoded by ARE-mRNAs may be advantageous for infection. Here, we discuss the development of a suite of sensitive and complementary assays to monitor ARE-mRNA turnover. These include luciferase- and destabilized-GFP-based assays that can be adapted for high-throughput screening applications.