Molecular Machines Unit
Unit Leader: Dr Till Böcking
Overview of Research
Our research focuses on elucidating the mechanisms of molecular machines in cellular assembly and disassembly processes using a combination of biochemical and biophysical approaches. In particular we develop fluorescence imaging approaches to visualise the dynamics of these processes at the single-molecule level. The advantage of single molecule measurements is that they can resolve the kinetics of processes without the need for synchronisation and permit the detection of short-lived intermediates in the reaction pathways that are otherwise averaged out in classical ensemble measurements. Our work draws on approaches from the physical sciences with development of microfluidic imaging devices, surface chemistry approaches and development of automated image analysis software.
Visualising chaperone-mediated processes
Molecular chaperones are molecular motors that drive a variety of intracellular assembly and disassembly processes to catalyse protein folding, prevent aggregation and facilitate the recycling of the components of macromolecular complexes. These functions are vital to cellular homeostasis and chaperone malfunction underlies a range of neurodegenerative diseases and cancers. However, the molecular mechanisms of these processes and how they can be targeted pharmacologically are not well understood. Capitalising on our recent single-molecule imaging approach to visualise chaperone dynamics (Figure1; Nat Struct Mol Biol 2011, 18(3), 295-301) we now aim extend our mechanistic studies of role of Hsp70 family chaperones in its diverse cellular functions.
Figure 1: Fluorescence imaging approach to follow in real time the chaperone-mediated disassembly of the protein coat surrounding endocytic clathrin coated vesicles.
Left: Selected snapshots from a time series (top) showing the fluorescence from clathrin and the chaperone Hsc70 in a coat visualised using the single-particle uncoating assay (shown schematically at the bottom).
Right: The plot shows intensity traces of the clathrin (blue) and Hsc70 (orange) signals of a single coat during the uncoating reaction.
Visualising transcriptional regulation
Transcriptional regulation is fundamental to the cell’s ability to modulate its gene expression in response to changes in its environment. In collaboration with A/Prof Dali Liu, a structural biologist at Loyola University (Chicago, IL, USA) we investigate a transcription factor controlling the expression of genes central to amino acid metabolism. Our aim is to elucidate the molecular mechanism of how the factor senses metabolite concentrations to effect transcriptional regulation. To achieve this goal we capitalise on single-molecule fluorescence imaging approaches to visualise its dynamics and interactions at the promoter that are required to initiate transcription.
Molecular design of interfaces
A long-standing interest is focused on controlling the properties of surfaces and materials at the molecular level using self-assembly chemistries. Our aim is to develop tools that enable us to investigate cellular processes quantitatively. Surface chemistry and nanotechnology also play in important role in devising strategies to capture and immobilise individual molecules or molecular assemblies for single molecule observation.
Unit Members
| Dr Till Böcking | Unit Leader, ARC Future Fellow |
| Dr Thomas Sobey | Postdoctoral Fellow |
| Ms Quill Bowden | Research Assistant |
| Mr Walid Al-Zyoud | Postgraduate student |
| Ms Siti Hawa Ngalim | Postgraduate student (Joint supervisor: A/Prof Gaus) |
Key Publications
Böcking T; Aguet F; Harrison SC; Kirchhausen T. Single molecule analysis of a molecular disassemblase: Mechanism of Hsc70-driven clathrin uncoating,
Nature Structural & Molecular Biology, 2011, 18 (3) 295-301 (cover article).
Xing Y; Böcking T; Wolf M; Kirchhausen T; Harrison SC. The structure of a clathrin coat with specifically bound Hsc70 and auxilin suggests a mechanism for Hsc70-facilitated disassembly,
EMBO Journal, 2010, 29 (3), 655-665.
Böcking T; Kilian KA; Reece P; Gaus K; Gal M; Gooding JJ. Substrate independent assembly of optical structures guided by biomolecular interactions,
ACS Applied Materials and Interfaces, 2010, 2 (11) 3270-3275.
Böcking T; Kilian KA; Gaus K; Gooding JJ. Modifying porous silicon with self-assembled monolayers for biomedical applications: the influence of surface coverage on stability and biomolecule coupling.
Advanced Functional Materials, 2008, 18, 3827-3833.
(+) Kilian KA; (+) Böcking T; Gaus K; Gooding JJ. Introducing distinctly different chemical functionalities onto the internal and external surfaces of mesoporous materials.
Angewandte Chemie, International Edition, 2008, 47, 2697-2699. (+) equal contribution
(+) Salomon A; (+) Böcking T; Gooding JJ; Cahen D. How Important Is the Interfacial Chemical Bond for Electron Transport through Alkyl Chain Monolayers?
Nano Letters, 2006, 6, 2873-2876. (+) equal contribution
Links
Funding Sources