PhD defense: Heidi Hansen

Using high-throughput CLIP technologies to study RNA assemblages coordinating mRNA expression

Supervision
Jan Christiansen, Associate professor, Copenhagen University

Exam Committee
Neus Visa, Professor, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University
Anders Lade Nielsen, Professor mso, Department of Biomedicine, Aarhus University
Jeppe Vinther, Associate Professor, Department of Biology, Copenhagen University

Abstract
The Insulin‐like growth factor‐2 mRNA‐binding protein (IMP) family has previously been implicated in multiple aspects of cellular function involving proliferation, differentiation, cell polarization and migration, illustrating the importance of RNA‐binding proteins in cellular and organismal fate. Using high-throughput technologies, such as RIP-seq and short and long-wave iCLIP, we were able to identify transcripts associated with cytoplasmic RNPs containing Drosophila Imp. The data revealed extensive binding to 3’UTR of transcripts co-ordinating the formation of filamentous actin, a process which is vital for the dynamics of the axonal growth cone during neuronal development. Upon further analysis we noticed that Imp also bound to the coding region of a subset of transcripts. Polysome analysis of these transcripts revealed a diminished translational elongation rate, indicating a role for Imp in the translational regulation of this subset of transcripts.