Nuclear RNA processing and surveillance. (360G-Wellcome-077248_Z_05_Z)

The aim of this project is to understand the quality control systems for nuclear RNA processing and ribonucleoprotein (RNP) assembly in yeast. We propose to analyse 1) the mechanisms of nuclear RNA degradation and RNP disassembly, 2) the features and signals used by surveillance activities to identify aberrant RNAs and RNP complexes and 3) the localisation of these activities. We have reproduced a key step in RNA degradation in vitro, by showing that a nuclear polyadenylation complex (TRAMP) can potently activate the exosome for RNA degradation. Functional characterisation of the factors and interactions involved in exosome activation will be analysed in vitro. The insights gained will underpin molecular genetic approaches in vivo to assess and compare the surveillance pathways that act during rRNA, mRNA, tRNA, snoRNA and snRNA synthesis. Our initial data indicate that common components are shared between these surveillance pathways. Chemical genomics will be used to identify degradation inhibitors, providing new tools for rapid in vivo analyses. Quantitative techniques will be used to quantify, model and interpret the data, particularly for ribosome synthesis. Cell biology approaches will be used to assess the localisation of the RNA degradation activities in vivo.