Development of optogenetic system for regulating transmembrane receptors and application

Abstract

Cells sense and transfer extracellular information to intracellular biochemical context through transmembrane receptors. External signaling molecules interact with cell surface receptors and regulate diverse intracellular processes. Because multiple-steps characteristic and complexity of signaling molecules, receptor mediated cellular functions were difficult to study in high spatiotemporal manner. In chapter 1, I established the optogenetic toolkits for regulating the activity of FGF receptor family (FGFR1-FGFR4) using Arabidopsis thaliana’s cryptochrome 2 homo-interaction. Extending concept of OptoFGFR1 to other members of FGFR family, I generated light-inducible FGF receptors, OptoFGFRs (OptoFGFR1-4). Using this fine-tuned module systems, I investigated the different role of FGFR signaling in endothelial cell migration and glia function, especially astrocyte activity. For further in vivo application, adeno-associated virus (AAV) was used for expression of optically-controlled receptor in the central nervous system. In chapter 2, I introduce OptoTGFBRs, a new optogenetic system to regulate Transforming growth factor β Receptor signaling pathway with spatiotemporal manner. Using blue light dependent hetero-interaction between Arabidopsis thaliana’s cryptochrome 2 and CIB1 protein, I develop chimeric TGF- $\beta$ receptor. Upon light illumination, OptoTGFBRs efficiently activates downstream signaling pathways, Smad2 phosphorylation and related gene expression.