Regulation of mRNA Fate

Project Summary This renewal application focuses on studying the roles of messenger RNA binding proteins (mRBPs) in the regulation of alternative splicing and mRNA translation. Our approach uses a combination of genomics, molecular biology and biochemistry to gain fundamental insights to mRBP function and targets in human cells. During the previous funding period we discovered functional RNA elements that control pre-mRNA splicing and mRNA translation. The goal of the next funding period is to determine how these sequences regulate gene expression. Another goal of this project is to determine how the process of alternative splicing impacts protein synthesis. It is well established that alternative splicing expands the coding potential of protein coding genes, but we and others have also discovered that mRNA isoforms can exhibit different patterns of translational control and mRNA stability. We will elucidate the mechanisms through which alternative splicing influences translation by discovering isoform-specific cis-acting RNA elements that influence polyribosome association. To accomplish this goal, we will use composite cell lines that contain a full complement of human and chimpanzee chromosomes. These novel models will enable the discovery of single nucleotide changes that cause allele- specific gene expression within the identical trans-regulatory environment. We can then determine the mechanisms of action for these regulatory elements using biochemical and molecular approaches, such as RNA affinity chromatography and mRNA reporter assays. Together, this project will significantly advance the understanding ofr how mRBPs function in post-transcriptional control of gene expression in human cells and provide key information for novel strategies to treat inherited diseases.