Structural dynamics of the human telomerase ribonucleoprotein complex

• Applicant: Dr. Martin Hengesbach
• Subject Area: Biophysics
• Term: from 2010 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 186107329

The telomerase complex prevents chromosomes from shortening during cell division in virtually all eukaryotic organisms, and plays an important role in aging processes as well as cancer. It helps preserve genomic stability and protects the ends of the chromosomes by synthesizing repeated DNA sequences to these ends. Among other proteins, it contains a specialized reverse transcriptase (“TERT”) and an RNA subunit (“TR”), which serves a dual role: it both provides a structural scaffold for TERT and other protein components, and contains the template sequence. Structural biology approaches have provided only limited information about the structure and dynamics of human TR (hTR) or functional telomerase RNP complexes. A powerful way to address RNA structure and dynamics is single-molecule fluorescence resonance energy transfer (smFRET). FRET may be used as a spectroscopic ruler to measure spatial distances between a fluorescent donor dye that exhibits a spectral overlap to an acceptor dye, both attached to the molecule of interest. Total internal reflection microscopy, laser excitation and a CCD camera allow detection and spectroscopic FRET analysis of surface-immobilized single molecules. This project aims to characterize the structure and dynamics of hTR using smFRET. Ligation approaches will be used to synthesize RNA constructs, which will be analyzed both in absence and presence of protein co-factors of the functional human telomerase complex. This will provide deeper insight into the mechanisms of this unique enzyme as well as the effects of pathogenic mutations.

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Professor Michael D. Stone, Ph.D.