Systems allowing inducible control of protein activities, allowing precise manipulation of signaling pathways, protein expression and other processes, have transformed experimental biology. While a number of studies have used chemicals to perturb such processes, in recent years scientists have developed light-responsive 'optogenetic'tools, which allow precise spatio- temporal control of activity. In recent work, we have developed a light-induced dimerization platform based on cryptochrome (CRY2) and its interacting partner CIB1 that allows control of protein-protein interactions and localization with light. Our initial characterization indicates that this system has distinct properties that will facilitate use in model organisms and in vivo, as it has fast kinetics, is reversible, and is entirly genetically encoded. The broad aims of this project are to further develop the CRY2-CIB1 dimerization technology such that it can be used in a broad range of biological applications. Specifically, we aim to engineer improved dimerizers that are smaller, monomeric, more tightly controlled, and have improved dynamic range (Aim 1).
In Aim 2, we will generate a 'toolkit'of optimized light-activated proteins, including a recombinase, a transcriptional activator, and a protease. Together, these enzymes will enable diverse approaches for regulation of biological activity at the levels of gene, RNA, and protein. A robust light-activated Cre recombinase, for example, would have enormous significance to neuroscience, developmental biology, and other fields, and would have widespread use in vivo in a variety of model systems.
In Aim 3, we will examine the properties of the CRY2-CIB1 system and light-activated enzymes for control of biological systems.

Public Health Relevance

The goal of this research is to develop novel tools for light-inducible control of protein activities. These tools, allowing precise spatial, temporal, and dose dependent control of biological processes, will open up vast new experimental avenues, allowing better understanding of pathways important in health and disease.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
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Special Emphasis Panel (ZRG1-IMST-L (90))
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Deatherage, James F
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University of Colorado Denver
Schools of Medicine
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Locke, Clifford; Machida, Kazuya; Tucker, Chandra L et al. (2018) Correction: Optogenetic activation of EphB2 receptor in dendrites induced actin polymerization by activating Arg kinase. Biol Open 7:
Cook, Sarah G; Bourke, Ashley M; O'Leary, Heather et al. (2018) Analysis of the CaMKII? and ? splice-variant distribution among brain regions reveals isoform-specific differences in holoenzyme formation. Sci Rep 8:5448
Pathak, Gopal P; Spiltoir, Jessica I; Höglund, Camilla et al. (2017) Bidirectional approaches for optogenetic regulation of gene expression in mammalian cells using Arabidopsis cryptochrome 2. Nucleic Acids Res 45:e167
Liu, Qi; Tucker, Chandra L (2017) Engineering genetically-encoded tools for optogenetic control of protein activity. Curr Opin Chem Biol 40:17-23
Taslimi, Amir; Zoltowski, Brian; Miranda, Jose G et al. (2016) Optimized second-generation CRY2-CIB dimerizers and photoactivatable Cre recombinase. Nat Chem Biol 12:425-30
Spiltoir, Jessica I; Strickland, Devin; Glotzer, Michael et al. (2016) Optical Control of Peroxisomal Trafficking. ACS Synth Biol 5:554-60
Schindler, Suzanne E; McCall, Jordan G; Yan, Ping et al. (2015) Photo-activatable Cre recombinase regulates gene expression in vivo. Sci Rep 5:13627
Hanson, M Gartz; Fregoso, Veronica L; Vrana, Justin D et al. (2014) Peripheral nervous system defects in a mouse model for peroxisomal biogenesis disorders. Dev Biol 395:84-95
Pathak, Gopal P; Strickland, Devin; Vrana, Justin D et al. (2014) Benchmarking of optical dimerizer systems. ACS Synth Biol 3:832-8
Taslimi, Amir; Vrana, Justin D; Chen, Daniel et al. (2014) An optimized optogenetic clustering tool for probing protein interaction and function. Nat Commun 5:4925

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