Photosensing with LOV: Molecular Insights into the Shared Mechanism of Light-Regulated Kinase Signaling between Plant Phototropins and Bacterial Two-Component Systems
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With the overall goal of understanding the basis of Light–Oxygen–Voltage (LOV) domain mediated signaling transduction pathways, my graduate research focused on characterizing the role of LOV domains in kinase signaling and the mechanism of signal propagation from LOV domains to a diverse set of downstream effectors. I started from the studies of the LOV domain regulated serine/threonine kinase activity from plant phototropins, later comparing this with LOV domains light–regulated histidine kinases in marine bacteria. Though the plant and bacterial kinases have diverse protein folds and functions, they both share the common photosensing module. Using a combination of biophysical and biochemical techniques, I examined the properties of these light mediated proteins and provided molecular insights in which light signal is transmitted from the core to the surface of the LOV domain. This work also presented detailed biochemical and biophysical characterization of the full–length LOV domain–containing histidine kinase, providing a solid foundation for studying the regulation of the LOV domain in the context of full–length protein. Taken together, I hope to address both the mechanisms that LOV domains use to regulate their effectors, and further how histidine kinases are regulated by their sensory domains. These are the central questions in both the LOV domain and the histidine kinase domain fields, and are of central importance to signal transduction in general.