Date: 17th April 2024
Time: 13:00
Title: Beyond Splicing: Unveiling Novel Roles of U1 snRNP in plants
Location: Lecture room B7, Forest Sciences Building, Latokartanonkaari 7-9
Host: Roosa Laitinen
Abstract: In eukaryotic organisms, the process of removing introns from pre-mRNA transcripts—a process known as splicing—is essential for gene expression and regulation. This intricate task is performed by the spliceosome, a complex molecular machinery, where the U1 small nuclear ribonucleoprotein (snRNP) plays a pivotal role in recognizing the 5' splice site and initiating spliceosome assembly. Although primarily known for its role in splicing, recent studies in metazoans have unveiled that the U1 snRNP carries out additional functions that are independent of its splicing activity. These findings have sparked interest in exploring similar splicing-independent roles in other eukaryotes, such as plants. However, research in this area has been hampered by the scarcity of genetic tools and a limited understanding of the proteins associated with plant U1 snRNPs.
I will present our attempts to provide mechanistic details on U1 complex compositions in the model plant Arabidopsis thaliana. We address this challenge by employing an RNA-centric methodology that allowed us to identify over 200 proteins associated with the Arabidopsis U1 snRNP. Notably, among these proteins, we found several that are involved in mRNA cleavage and polyadenylation, processes that are crucial for defining the mRNA 3'-end and consequently for mRNA stability and translation efficiency. Our findings reveal that the disruption of core U1 snRNP components in Arabidopsis leads to aberrant premature cleavage and polyadenylation within gene bodies, as well as the selection of alternative polyadenylation sites in 3’ untranslated regions (3'-UTRs). These results highlight the intricate role of U1 snRNP beyond splicing, particularly in the regulation of mRNA 3'-end processing. By providing a detailed map of U1 snRNP-associated proteins and uncovering their novel functions in mRNA processing, our study lays a foundational framework for a deeper understanding of the diverse roles of U1 snRNPs in plants
Sascha's team is interested in the regulation of RNA processing in plants an how it contributes to plant stress resistance. They are particularly interested in post-transcriptional mechanisms that ensure survival under stress conditions.