"Eukaryotic gene expression is tightly regulated at all stages of the mRNA life cycle, from mRNA synthesis in the nucleus to mRNA degradation in the cytoplasm. Defects in gene regulation cause serious defects in cells, and severe pathologies in humans, such as cancer, diabetes, and cardiovascular disease. The host lab recently made the seminal discovery that mRNA synthesis and degradation are coupled processes. The nine-subunit Ccr4-Not complex emerged as a candidate for a so far elusive coupling factor: in contrast to most mRNA processing proteins that act at only a single step in the mRNA life cycle, Ccr4-Not acts throughout the mRNA life span in mRNA synthesis, transport, translation and degradation. Despite its importance, the function of Ccr4-Not in mRNA synthesis is poorly understood. Although a recent publication suggested that Ccr4-Not could rescue stalled RNA polymerase and thereby advance transcription, the rescue mechanism remains enigmatic.Our key research objectives are a comprehensive structure-function analysis of Ccr4-Not in complex with transcribing RNA polymerase II, determination of the genome-wide mRNA-protein contacts that Ccr4-Not undergoes, and ultimately a description of the mechanisms by which the by Ccr4-Not promotes transcription and regulates the mRNA lifecycle.The host’s broad multi-disciplinary expertise and the established state-of-the-art techniques uniquely position us to achieve our ambitious objectives. All required protein complexes can be purified in milligram amounts. We will employ an innovative combination of cutting-edge methods such as high-resolution cryo-electron microscopy, molecular interactions assays, isotope-tagged cross-linking, proteomics, genome-wide RNA interaction assays in vivo, and bioinformatics.We expect our results to significantly advance the knowledge in the fields of mRNA synthesis and mRNA life cycle regulation. This is turn may provide new opportunities for medical research and drug design."