Ca^<2+> channelplexes : assembly in the membrane and physiological significance

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Ca^<2+> as a second messenger controls a wide variety of biological responses and contributes to formation of tissues such as bones, thereby playing a central role in regulating "homeostasis" at whole body, tissue, and cell levels. In my research, I have focused on voltage-dependent Ca^<2+> channels (VDCCs) and transient receptor potential (TRP) channels to aim at understanding mechanisms, that underlie formation and assembly at the biomembrane of Ca^<2+> channel protein complexes (Ca^<2+> channelplexes), and their physiological significance. Firstly, I have unveiled several unique activation mechanisms, that regulate cellular signal transduction for TRP Ca^<2+>-permeable caion channels. Secondly, I have demonstrated that channel proteins act not only as Ca^<2+>-permeating apparatus but also as assembly centers for receptors, signal-regulating proteins, and scaffolding proteins. Thirdly, important roles of Ca^<2+> channel protein complexes via formation of feedback regulation pathways in signal transduction have been demonstrated. Finally, I have also shown physiological significance of Ca^<2+> channelplexes at tissue levels. TRPC3 channelplexes in B lymphocyte activation and P/Q type VDCCplexes in presynaptic vesicle fusion are examples of the outcome of this study. Thus, my study clarifies how individual Ca^<2+> channels play roles in unique cellular responses.