NSF-MCB/BSF - Composition and Stoichiometry of mRNA-protein Complexes Leading to Nuclear Export and Gene Expression Regulation

University Of California-Davis, Davis CA

Investigators

Abstract

Gene expression in eukaryotic cells (e.g., human or plant cells) requires export of messenger RNA (mRNA) carrying genetic information from the nucleus to the cytoplasm where it can be translated into proteins. In this collaborative project, the PIs will investigate the molecular machinery that enables mRNA transport from one cellular compartment to another in two model systems, yeast (S. cerevisiae) and human cells. The research will increase fundamental understanding of the mechanisms and regulation of gene expression, which is central to knowing how any organism functions in a changing environment. These outcomes can have beneficial societal impacts, e.g., through development of new biotechnology applications. The project will also engage a diverse group of students to provide training, skills, and experiences in scientific research and promote their participation in STEM careers. RNA is a centerpiece of the gene expression pathway that, as a functional unit, is bound by proteins in a ribonucleoprotein particle (RNP). This project focuses on nuclear messenger (m)RNP assembly, which is critical for mRNA export from the nucleus. It is recognized that the protein components of a mRNP are dynamic, and gene-specific mRNPs have varying processing and nuclear export efficiencies, yet it is not known what protein architectures define an export-competent mRNP. The PIs will employ single particle imaging techniques to investigate what protein-mRNA architectures support mRNP export during cell growth and stress in yeast and mammalian systems. They will further characterize the recruitment of mRNP constituents to the site of transcription in order to develop spatial and kinetic models of mRNP assembly. New knowledge expected to emerge from this research includes protein stoichiometry and co-occupancy data for individual mRNPs, information on where and when those proteins are assembled into an mRNP, and identification of transcript features that lead to regulated mRNP export during stress. The outcomes will further understanding of gene expression regulation and how reprogramming mRNP structure-function could support changes in cell function. This collaborative US/Israel project is supported by the US National Science Foundation and the Israeli Binational Science Foundation. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.