hahn lab

LOV fusion


A photoactivatable Rac1 (PA-Rac1) produced by fusing Rac1 to the LOV domain. In the dark, when the Jα is intact, LOV sterically binds the Rac1 active site. Upon irradiation, the Jα heliz unwinds, prducing a larger linker between Rac and LOV.

LOV is photoactivated very rapidly (< 0.5 milliseconds). The half time for return to the dark state can be adjusted using point mutations (in our hands from 1.7 to 496 seconds, Curr. Protoc. Cell Biol., 73: 21.10.1-14, 2016). Rapid return times are useful for precise kinetic control. Slower return times enable continuous activation with only a brief pulse of light every few minutes.


Description of the approach

Wu, Y, Frey, D., Lungu, O. I., Jaehrig, A., Schlichting, I., Kuhlman, B. and Hahn, K.M. A genetically-encoded photoactivatable Rac reveals spatiotemporal coordination of Rac and Rho during cell motility. Nature, 461: 104-110, 2009. PMC2766670. Online article | Free PMC article


Additional applications

Yoo, S.K., Deng, Q.,  Cavnar, P. J.,  Wu,Y.I.,  Hahn, K.M., Huttenlocher, A. Differential Regulation of Protrusion and Polarity by PI(3)K during Neutrophil Motility in Live Zebrafish.  Developmental Cell, 18(2):226-236, 2010. PMC2824622. Online article | Free PMC article

Wang, X., He L, Wu, Y.I., Hahn, K.M., and Montell, D.J. Light-mediated activation reveals a key role for Rac in collective guidance of cell movement in vivo. Nature Cell Biol., 12(6):591-7, 2011. PMC2929827. Online article | Free PMC article

Dietz, D.M., Sun, H., Lobo, M.K., Cahill, M.E., Chadwick, B., Gao, V., Koo, J.W., Mazei-Robison, M.S., Dias, C., Maze, I., Damez-Werno, D., Dietz, K.C., Scobie, K.N., Ferguson, D., Christoffel, D., Ohnishi, Y., Hodes, G.E., Zheng, Y., Neve, R.L., Hahn, K.M., Russo, S.J. and Nestler, E.J. Rac1 is essential in cocaine-induced structural plasticity of nucleus accumbens neurons. Nature Neurosci., 15(6): 891-896, 2012.  PMC3565539. Online article | Free PMC article

Hayashi-Takagi, A., Yagishita, S., Nakamura, M., Shirai, F., Wu, Y.I., Loshbaugh, A.L., Kuhlman, B., Hahn, K.M., and Kasai, H. Labelling and optical erasure of synaptic memory traces in the motor cortex. Nature, 525(7569): 333-8, 2015.  PMC4634641. Online article | Free PMC article


Detailed Method

Wu, Y.I., Wang, X., He, L., Montell, D. and Hahn, K.M. Spatiotemporal control of small GTPases with light using the LOV domain. Methods Enzymol., 497: 393-407, 2011.  PMC3407667. Online article | Free PMC article

 

©2018 UNC Department of Pharmacology