Grant: CIHR Fellowship

Drosha is a conserved ribonuclease that cleaves stem-loop RNA structures and is well-known for its role in microRNA (miRNA) biogenesis. However, Drosha has recently been shown to cleave non-miRNA targets, influencing RNA stability and/or transcription termination. Yet, these emerging new roles of Drosha remain poorly understood. Here we propose to study new Drosha functions by using a simple eukaryote model system: the fission yeast Schizosaccharomyces pombe, a model that allows powerful genetic screens and high-throughput analysis that are expected to produce critical insights in the understanding of Drosha functions in other organisms, including mammals. Our preliminary in silico screening for Drosha-like stem-loop structures in the S. pombe transcriptome revealed several putative targets in mRNA genes (both in introns and exons). Thus, the central hypothesis underlying my project is that Pac1, the S. pombe Drosha homolog, targets mRNAs to control key biological processes.