Peter, Stephen (2022)
Characterization of posttranscriptional regulation elements – From protein degradation to functional RNA structures.
Technische Universität Darmstadt
doi: 10.26083/tuprints-00021195
Dissertation, Erstveröffentlichung, Verlagsversion

Kurzbeschreibung (Abstract)

Posttranscriptional gene regulation in eukaryotic cells is one of the most important mechanism in complex life to either control protein synthesis or diversity at any given moment in the life of a cell. Consequently, deregulation of the many processes involved in posttranscriptional regulation can lead to severe diseases, such as Alzheimer’s disease or certain types of cancer. RNA-binding proteins (RBPs) can also facilitate alternative splicing (AS), which increases protein diversity and fine tunes the protein amount and function in the case of different stress conditions. A deregulation of AS events can lead to severe diseases, such as Parkinson’s disease or certain cancer variants. I characterized a newly described mechanism, where AS events are coupled to rapid protein decay. We termed this event AS-CPD, alternative splicing coupled to constitutive protein decay. The protein decay signal (degron) found in mammalian cells is also functional in Saccharomyces (S.) cerevisiae and Escherichia (E.) coli cells. It is dependent on hydrophobic amino acids in the C-terminus and has the capability to rapidly and efficiently reduce the amount of the tagged protein to an undetectable amount in mere minutes. This mechanism might be due to a conserved stress response in the tested organism. The degron described in this thesis could be a potential tool for new kinetic analysis. Major players in posttranscriptional regulation are trans-acting RBPs, such as Roquin or AUF1. Roquin is a key regulator in immune homeostasis and recognises stem-loop (SL) structures in 3’-UTRs (untranslated regions) to destabilise certain messenger RNAs (mRNAs). In this study, we found, that Roquin can recognise not only classical constitutive decay elements (CDEs), but also AU-rich decay element (ARE)-like CDEs. The binding of these elements may also be subject to competition between different RBPs, as it is in the case of the UCP3 3’-UTR CDEs. Here, Roquin and AUF1 compete for the binding to CDE1. RNA structure often implies a certain function in the organism. The pandemic causing virus SARS-CoV-2 is an RNA virus with a 30 kb long heavily structured genome. The many SLs in the 5’- and 3’-UTRs fulfil different essential functions, which are partially unknown. Here, we provide a detailed analysis of the structure of the genome and impose a screen of chemical compounds with the ability to bind RNA. We found a potent binder D01 with the ability to bind the pseudoknot in between the two open reading frames (ORFs) 1a and 1b, which encode different and essential parts of the viral proteome. These compounds might be a precursor for future potent drugs, able to target RNA viruses with structured genomes.

Frage zum Eintrag

Redaktionelle Details anzeigen