Imaging transcription factor DNA target search in a living cell

Researcher

Project Details

Transcription factors have evolved DNA target search strategies that allow them to efficiently navigate the nuclear space and arrive at their specific DNA sequence. This target search strategy is underpinned by molecular diffusion, which in turn is controlled by the architectural organisation of the cell nucleus and oligomeric state of the transcription factor. Until recently no imaging approach could track the molecular mobility of protein oligomers within the nuclei of live cells. To address this research gap we recently established a new microscopy method to image the transport and binding dynamics of different oligomeric species in live cells (Hinde et al. 2016. Nature Comm. 11047). The overall aim of this project is to use to use this technology to uncover how the spatial compartmentalisation of the cell nucleus regulates transcription factor complex formation and DNA target search in a living cell.

imaging transcription factor diffusion in a living cell
Figure 1: Imaging transcription factor diffusion in a living cell. a. The architectural organisation of the cell nucleus (blue signal highlights a snapshot of the DNA network) can be recovered from the diffusive route a population of fluorescent molecules adopt inside this complex environment (green signal). In particular, a nuclear factor’s DNA target search strategy (red star indicates target) can be observed by sampling its change in position (green spots dispersing from the central position within the grid) at a rate that is much faster than the time it takes each to perform the entire journey. b-c. Here we track the diffusive route of a transcription factor (STAT3) before (b) and after (c) transcriptional activation by: (1) tagging this transcription factor to a fluorescent protein (GFP) and (2) mapping its 'connectivity' (zoomed insert) throughout the nucleus via a spatiotemporal correlation analysis (Scale bar = 2 micrometer) .

Researchers

Jieqiong Lou, Post doctoral researcher

Julia Ivanova, Masters research student

Collaborators

Professor Enrico Gratton, University of California, Irvine, USA.

Associate Professor Marie Bogoyevitch, University of Melbourne, Australia.

Professor David Jans, Monash University, Australia.

Funding

ARC Discovery Project (2018-2021) 'Nuclear architecture in a living cell facilitates navigation of the genome'.

Research Publications

Hinde E,  Pandzic E, Yang Z,  Ng IHW,  Jans DA,  Bogoyevitch MA, Gratton E, Gaus K. Quantifying the dynamics of the oligomeric transcription factor STAT3 by pair correlation of molecular brightness. Nature Communications 2016; 7(11047).

Research Group

Hinde laboratory: Biophysics of Nuclear Organisation



Faculty Research Themes

Cancer

School Research Themes

Cancer in Biomedicine, Cellular Imaging & Structural Biology, Molecular Mechanisms of Disease



Key Contact

For further information about this research, please contact the research group leader.

Department / Centre

Biochemistry and Molecular Biology

Unit / Centre

Hinde laboratory: Biophysics of Nuclear Organisation


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