hahn lab

embedded peptide

Optogenetic control of endogenous signaling can be an important tool for probing cell behavior. Using the photoresponse of LOV2, we developed analogues of kinase inhibitors whose activity is light dependent. Inhibitory peptides were appended to the Jα helix, where they inhibited kinases in the light but were sterically blocked from kinase interaction in the dark. In the example shown here PKI (red) is an inhibitor of PKA (green). The LOV domain is shown in blue.

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

Lungu, O.I., Hallett R.A., Choi E.J., Aiken M.J., *Hahn K.M., *Kuhlman B. Designing Photoswitchable Peptides Using the AsLOV2 Domain. Chemistry and Biology, 19(4):507-17, 2012. PMC334866. Online article | Free PMC article

Yi, J.J., Wang, H., Vilela, M., Danuser, G., and Hahn, K.M. Manipulation of endogenous kinase activity in living cells using photoswitchable inhibitory peptides. ACS Synth. Biol., 3(11):788-95, 2014. PMC4277778. Online article | Free PMC article

Yumerefendi, H., Dickinson, D.J., Wang, H., Zimmerman, S., Bear, J.E., Goldstein, B., *Hahn, K. and *Kuhlman, B. Control of protein activity and cell fate specification via light-mediated nuclear translocation. PLoS One, 10(6): e0128443, 2015. PMC4471001. Online article | Free PMC article

Additional applications

Yumerefendi, H., Lerner, A.M., Zimmerman, S.P., Hahn, K.M., Bear, J.E., Strahl, B.D. and Kuhlman, B. Light-induced nuclear export reveals rapid dynamics of epigenetic modifications. Nature Chem. Biol., 12(6): 399-401, 2016. PMC488806. Online article | Free PMC article

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