PROJECT SUMMARY/ABSTRACT Perturbations in cholesterol homeostasis are major contributors to cardiovascular disease and associated comorbidities. The objective of this proposal is to define the role of RNA-binding proteins in cholesterol metabolism and atherosclerosis. Interactions between RNA-binding proteins and non-coding RNAs may affect transcriptional outputs at specific genetic zip codes, either locally or across multiple chromosomes. Reinforcing this premise, our preliminary studies suggest that the transcriptional coactivator and RNA-binding protein Raly interacts with the noncoding RNA LeXis to modulate the expression of cholesterol biosynthetic genes. Capitalizing on this novel insight, we aim to investigate the contributions of RALY in sterol metabolism. In Aim 1, we define the physiologic role of Raly in cholesterol metabolism and contributions to atherosclerosis development. We will test out hypotheses by studying mice with tissue specific deletion of Raly or mice transduced with gain- or loss-of-function adenoviral vectors. In Aim 2, we will investigate the mechanisms by which RALY influences gene expression. Utilizing unbiased genome wide approaches will map potential Raly binding sites, its influence on chromatin architecture and decipher its cooperative and hierarchical relationship with transcriptional modulators. These studies are expected to shed fundamental insight into mechanisms controlling metabolic regulation while exploring novel opportunities for therapeutic intervention.