Scheme: University Research Fellowship
Organisation: University of Oxford
Dates: Oct 2013-Sep 2016
Summary: The small heat-shock proteins are a family of virtually ubiquitous stress proteins, with the majority interacting with non-native states of proteins. This property is fundamental to their general behaviour as molecular ‘chaperones’, acting to prevent improper polypeptide associations and aggregation. Molecular chaperones thereby play a vital role in protein homeostasis, the mechanism through which the cell maintains proper function by balancing the influence of a multitude of biochemical pathways. sHSPs represent a central node in this ‘proteostasis’ network, and are in the main dramatically up-regulated under stress conditions. Furthermore, they are often found associated with protein aggregates obtained post-mortem from sufferers of protein-misfolding disease. Despite their crucial contribution to the body’s tolerance to stress, structural information on the sHSPs, and the interactions they make with target proteins and other components of the cell, has proven hard to come by due to their intrinsically heterogeneous and dynamic structure.
Using a combination of approaches we are determine the thermodynamics and kinetics of protein self-assembly. This has allowed us to investifage the underpinnings of function on structure and dynamics. Our most exciting research outcome has been the (unpublished) discovery of how proteins can avoid functional interference upon gene duplication. This is the first structural explanation for this phenomenon, which has been the focus of research by many groups worldwide, and will lead to (we hope) a very high-impact publication. We have also developed a new research direction in studying the association of mammalian sHSPs to cardiomyopathy, leading to new bench-to-bedside collaborations within Oxford and a novel drug lead.
Dates: Oct 2008-Sep 2013
Summary: To understand protein function we need to not only understand protein structure, but also to focus on their dynamic aspects. This includes their synthesis, folding into functional or pathogenic forms, interactions with other cellular components, and degradation. After their synthesis, the folding of many protein chains into the correct functional arrangements often requires assistance by members of the molecular chaperones. These species also have a vital role to play during conditions where the cell is stressed, by preserving and subsequently repairing damaged proteins. The mechanism by which they carry out these housekeeping duties is not fully understood, yet malfunctioning of this system results in a variety of diseases and even premature death. In our current research we are focussing on the least well understood family of the molecular chaperones, the small heat-shock proteins (sHSPs). In addition to their chaperone function, members of these proteins have been implicated in various diseases including cataract, motor neuropathy, and Alzheimer’s. We are examining how these proteins behave and interact with substrates under stress conditions, and how they fit into the overall chaperone network in the cell. We have shown the sHSPs to be very dynamic which, coupled to their large size, has hampered conventional approaches to their study. However, as we are concurrently developing and employing mass spectrometry strategies for the study of these proteins, it is our goal to monitor their reactions in real time, and moreover, in conditions which closely mimic the cell. In this was we are delineating the reaction network, associated kinetics, and structural characterisation of the sHSPs chaperone system. This will open the door for us to examine the effect of variants of these proteins and their substrates on the global chaperone network, thereby gaining novel insight into the pathologies of the associated disease states.