Mechanisms of TRPV1 channel gating and modulation by temperature and vanilloids

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My long-term goal is to establish an independent research group aimed at understanding allosteric signaling in membrane proteins. I intend to focus on Transient Receptor Potential (TRP) cation channels as a model system, as they exhibit fascinating allosteric behaviors that have important consequences for diverse physiological processes. One of the best characterized TRP channels is the TRPV1. The activation of this channel in nociceptor terminals by noxious environmental stimuli, including burning heat, leads directly to the perception of pain, and can contribute to the development of inflammatory hyperalgesia. All these processes ultimately depend on the opening and closing (i.e. gating) of the cation-conduction pathway in the pore of TRPV1, and its control by positive and negative modulators. We currently lack a mechanistic understanding of the process of TRP channel gating, as well as of the mechanisms through which gating is controlled by important stimuli such as temperature and vanilloids. This project will first aim to identify the regions of the channel that directly control gating of the pore. Second, it will aim at determining whether the extracellular half of the pore forms the temperature sensor. Third, it will aim at elucidating the mechanisms through which distinct vanilloid compounds can either activate or inhibit the TRPV1 channel. This has important consequences for the effects of TRPV1-targetted analgesic drugs on thermoregulation, and for the function of endogenous pro-inflammatory activators of TRPV1. Finally, I will engineer sensitivity to vanilloids into the TRPV2 channel and study whether the mechanisms of channel modulation by these molecules are conserved between V1 and V2. The three aims will be addressed with a combination of electrophysiological measurements of channel activity, site-directed mutagenesis, computational biophysics and structural information. The mentored part of the award will allow me to obtain the necessary training to understand computational biophysics approaches and rigorously apply them to my future research. This will complement my training as an experimental physiologist, providing me with an extended conceptual framework and a set of practical tools to investigate protein function at the level of structural dynamics at atomic scales. I consider that the integration of protein structure, function and dynamics is necessary to fully comprehend the mechanisms that govern allosterism in proteins, and I therefore consider that the training that I will obtain will be fundamental for my career. In addition, training in the Swartz lab, one of the leading laboratories worldwide in ion channel research, will strengthen my expertise in electrophysiology and broaden my overall scientific perspective.