Optogenetic Cell Biology and Biochemistry
Optogenetics involves the combined use of light with genetically engineered modules to control cellular and molecular processes. Our lab works to engineer new protein-based tools to control protein interactions and activity with light. As light is an ideal actuator, light-regulated systems allow spatial, temporal, dose-dependent, and reversible control.
Cryptochrome 2 optogenetic tools
We pioneered use of the plant cryptochrome protein CRY2, along with a light-dependent interactor, CIB1, to generate the CRY2/CIB1 photodimerizer system. This system allows fast and local regulation of protein localization and/or activity using light.
We are using the CRY2/CIB1 dimerizers to regulate activity of basic cellular processes, including transcription, DNA recombination, and protease activity. We are also working to further optimize the dimerizer modules and develop ways to use light to regulate enzymatic activities and signal transduction pathways, build new tools for neuroscience and cellular biology.
See: Kennedy et al., 2010 Nature Methods
Control of protein-protein interactions with light using CRY2/ CIB1 system. (A) Cytosolic CRY2-mCherry is recruited to a membrane-localized CIB1 fragment upon light application. (B) Localization of CRY2-mCherry before and 20s after recruitment.
Optogenetic Control of Transcription
We used the CRY2-CIB1 interaction to reconstitute a split Gal4BD-VP16AD transcription factor, allowing robust induction of transcription with light.
See: Pathak et al., 2014; Hughes et al., 2012; Kennedy et al., 2010
We also developed a method to block transcription factor activity with light in mammalian cells. See: Pathak et al., 2017
Optogenetic Control of Cell Death
Cells expressing MLKL(1-140)-CRY2 stimulated with light at start of video.
We used light-induced CRY2 clustering to regulate activity of a cell death protein called MLKL. MLKL, an executioner protein involved in the final stages of necroptosis, is normally triggered by oligomerization. We replaced its normal regulatory domain with CRY2 to generate a version in which light induces cell death.
See: Taslimi et al., 2022