Structural biology of the mRNA interactome and TRIM proteins

• Applicant: Professor Dr. Janosch Hennig
• Subject Area: Structural Biology ; Biophysics ; Developmental Biology
• Term: from 2015 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 267437786

Protein-RNA recognition during posttranscriptional regulation of gene expression is essential for many biological mechanisms including stem cell development and differentiation in metazoans. It is still an unsolved question how a limited set of RNA binding proteins can selectively bind and regulate different mRNAs with similar target sequences. Recently, tripartite motif protein (TRIM) family proteins, which have been known to play a role in ubiquitin signalling, have been identified as novel RNA binding proteins. Human, Drosophila and C. elegans orthologs of TRIM71 and TRIM32 specifically bind mRNA and regulate the translation of transcription factors involved in stem and progenitor cell development via interaction with the miRNA-induced silencing complex (miRISC). The molecular mechanisms of RNA recognition of these proteins and TRIM-mediated ubiquitylation linked to stem cell development is unknown. The goal of this project is to employ integrated structural biology to provide a molecular understanding of RNA recognition and regulation of ubiquitin signalling by TRIM proteins. A combination of structural biology methods is important to characterize the structure and dynamics of TRIM proteins, which are multi-domain proteins with intrinsically disordered linker regions. The interaction with recently identified binding partners for TRIM71 and TRIM32 orthologs will help to understand structural mechanisms of these proteins. Integrated structural biology combining X-ray crystallography, NMR, cryo-electron microscopy, and small-angle scattering will be combined with cell biology (in collaboration) to obtain a TRIM high-resolution structure in complex with RNA and other binding partners and to confirm its significance in a cellular environment. The proposed research will contribute greatly to the understanding of protein-RNA recognition and gene silencing during stem cell development.

• DFG Programme: Independent Junior Research Groups
• Major Instrumentation: Proteinaufreinigungsanlage
• Instrumentation Group: 1350 Flüssigkeits-Chromatographen (außer Aminosäureanalysatoren 317), Ionenaustauscher