title: Spatiotemporal control of cell signalling using a light-switchable protein interaction.
abstract: Genetically encodable optical reporters, such as green fluorescent protein, have revolutionized the observation and measurement of cellular states. However, the inverse challenge of using light to control precisely cellular behaviour has only recently begun to be addressed; semi-synthetic chromophore-tethered receptors and naturally occurring channel rhodopsins have been used to perturb directly neuronal networks. The difficulty of engineering light-sensitive proteins remains a significant impediment to the optical control of most cell-biological processes. Here we demonstrate the use of a new genetically encoded light-control system based on an optimized, reversible protein-protein interaction from the phytochrome signalling network of Arabidopsis thaliana. Because protein-protein interactions are one of the most general currencies of cellular information, this system can, in principle, be generically used to control diverse functions. Here we show that this system can be used to translocate target proteins precisely and reversibly to the membrane with micrometre spatial resolution and at the second timescale. We show that light-gated translocation of the upstream activators of Rho-family GTPases, which control the actin cytoskeleton, can be used to precisely reshape and direct the cell morphology of mammalian cells. The light-gated protein-protein interaction that has been optimized here should be useful for the design of diverse light-programmable reagents, potentially enabling a new generation of perturbative, quantitative experiments in cell biology.
authors.affiliation: The Cell Propulsion Lab, UCSF/UCB NIH Nanomedicine Development Center, University of California, San Francisco, California 94158-2517, USA.
authors.forename: Anselm
authors.initials: A
authors.lastname: Levskaya
authors.forename: Orion D
authors.initials: OD
authors.lastname: Weiner
authors.forename: Wendell A
authors.initials: WA
authors.lastname: Lim
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Voigt
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism*; D051792:Basic Helix-Loop-Helix Proteins / Q000737:chemistry / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism / Q000528:radiation effects; D048430:Cell Shape / Q000528:radiation effects; D003116:Color; D003599:Cytoskeleton / Q000378:metabolism / Q000528:radiation effects; D007259:Infrared Rays; D007700:Kinetics; D008027:Light; D051379:Mice; D041681:NIH 3T3 Cells; D010777:Photochemistry; D051939:Phytochrome B / Q000378:metabolism*; D011485:Protein Binding / Q000528:radiation effects; D021381:Protein Transport / Q000528:radiation effects; D015398:Signal Transduction / Q000528:radiation effects*; D013379:Substrate Specificity / Q000528:radiation effects; D013997:Time Factors; D020741:rho GTP-Binding Proteins / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D051939:Phytochrome B; D020741:rho GTP-Binding Proteins; C116162:PIF3 protein, Arabidopsis