Project description
Mechanistic insight into the post-transcriptional control of RNA
Eukaryotic cells have evolved various mechanisms for ensuring the quality of their genetic information at all levels. The RNA exosome complex constitutes such a mechanism with a central role in several aspects of eukaryotic RNA biogenesis, including RNA maturation and surveillance. It is involved in RNA quality control in the nucleus and degrades aberrant RNA molecules that have not matured properly. The scope of the EU-funded EXOonRNA project is to understand how the RNA exosome identifies and eliminates non-functional RNAs. Researchers will undertake a multidisciplinary approach to delineate the underlying mechanisms and provide answers related to the timely function of this complex in RNA decay.
Objective
The human genome is ubiquitously transcribed into far more RNA than is immediately needed. Consequently, RNA turnover becomes critical for keeping our cells healthy. The nuclear RNA exosome degrades the majority of short-lived RNA species within cell nuclei and is hereby the gatekeeper of an enormous RNA synthesis output. To perform this essential task, the exosome employs so-called ‘adaptor complexes’ (ExoACs), which contribute to target specificity. While the trimeric nuclear exosome targeting (NEXT) complex is specifically required for the degradation of short RNA transcripts, the poly(A) tail exosome targeting (PAXT) connection recruits the exosome to longer polyadenylated RNAs. Interestingly, and in contrast to NEXT, PAXT exhibits a rather complex nature. Besides the integral component RNA helicase MTR4 and the large scaffolding protein ZFC3H1, the proteins PABPN1, ZC3H3, and RBM26/27 participate in the RNA-targeting of PAXT. How assembly of all these proteins is achieved to commit a polyadenylated RNA for decay and how it is balanced with other nuclear RNA metabolic processes to avoid untimely decay of mRNA is unknown.
Here, I will track the interaction of the RNA-binding components of NEXT and PAXT with newly synthesized RNA in human cells using a novel and cutting-edge temporally resolved CLIP (T-CLIP) methodology, which combines nascent RNA labeling using photoactivatable ribonucleoside analogue 4-thiouridine with the time course of UV crosslinking of protein-RNA complexes. Since the T-CLIP approach allows us to link ExoAC interaction profiles to RNA synthesis and turnover data, I will define the positioning and timing of ExoAC component interactions with nuclear RNA in real-time to understand how nuclear exosome identify and eliminate nonfunctional RNA. In achieving my aim, I will critically further our understanding of how the cells in our bodies manage to quality control their genetic information through the post-transcriptional control of RNA levels.
Fields of science
Programme(s)
Funding Scheme
MSCA-IF-EF-ST - Standard EFCoordinator
8000 Aarhus C
Denmark