Advancing cryo-EM technology to address difficult biological questions

ABSTRACT Technological breakthroughs in single particle cryo-electron microscopy (cryo-EM) have enabled atomic structure determinations of many challenging biological macromolecules in an unprecedented rapid pace. It also facilitated addressing challenging structural biology questions that would otherwise be difficult to address. Beyond atomic structures, protein dynamics and conformational transitions between functional states are among questions that are particularly suited to be studied by single particle cryo-EM. TRPV1 ion channel is polymodal nociceptor that integrates signals generated from a range of biochemical and biophysical stimuli. It is biochemically well-behaved and physiologically and pharmacologically well characterized. With various endogenous stimuli and natural exogenous compounds trapping the channel in various functional states, we have determined structures of TRPV1 in various stable conformations. In the next step, we will use TRPV1 as a model system to exploit using novel cryo-EM advances to probe the range of conformational states sampled by this complex signal integrator. For many other TRP channels, in which there is no suitable pharmacological tools to trap the channels in specific stable conformations, methods developed with the model system can be used to study mechanisms of channel gating.