PROJECT SUMMARY It is the long-term mission of my lab to decipher the critical regulatory networks that govern post-transcriptional gene regulation during innate immunity with the goal that such knowledge significantly contributes to our scientific understanding of human health and disease. The innate immune system is comprised of a collection of environmental sensors and downstream signaling components that orchestrate a response to cellular insults and stress. A hallmark of innate immune activation is the transcriptional upregulation of the type-I interferons triggered by the sensing of pathogen-associated or damage-associated molecules. Research on innate immunity has traditionally focused on understanding the initiating triggers and signal transduction events that ultimately modulate the expression of a central set of interferons and cytokines. However, much less is known about the post-transcriptional gene regulatory layer, which acts to refine innate immune activation at the RNA level ? shaping gene expression to allow for a robust but finite host response while simultaneously preventing aberrant or pathogen-associated gene expression. This is a striking gap in our understanding given that many aspects of host-pathogen interactions have at its core the detection and suppression of foreign nucleic acids. It is becoming increasingly clear that RNA-binding proteins (RBPs) can pre-program the sensitivity of cells to immunogenic stimuli, as well as being essential factors in the anti- viral response. In part, much of the challenge has been an inability to query this layer of gene regulation in a comprehensive and systematic way, a necessary prerequisite when it comes to studying RBP biology. My training and expertise in RNA/DNA binding protein biochemistry and ?omic scale biology has allowed me to develop the necessary tools and reagents that I have now established in my laboratory to deeply understand post-transcriptional gene regulation in innate immunity. We are interested in pursuing the following major biological questions: 1)How do RNA-binding proteins regulate gene expression of their targets during an innate immune response? 2)What is the nature and impact of RNA methylation on mRNAs upon interferon/cGAMP stimulation? And how do such changes affect RBP assembly and function? 3) How are the genomes of RNA viruses deployed during the early stages of infection, and what host- or viral-encoded RNA-binding proteins facilitate this process? 4) What are the regulatory co-factors required for the activating or repressing cGAS-STING signaling? and can we identify small molecule compounds for the development of experimental probes and pre- therapeutic scaffolds?